LG958L Training Material Chapter III Engine: Tuesday, May 19, 2015

LG958 G958L L Train rainin ing g Mater Materia iall Chapter III Engine Tuesday, May 19, 2015

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RELIABILITY IN ACTION

CONTENTS Overview of Engine System Basic Structural Principle of DDE Engine Engine block group Crank-link mechanism Valve mechanism Fuel system Cooling system Lubrication system Electronic control system Cause Judgment and Troubleshooting Troubleshooting for Common Malfunctions of Engine System 2


Chapter III Structural Theory Theor y of LG958L Engine System System (DDE) Section I Overview Over view of Engine System I. Introduction of Main Parameters I. Model Explanation

BF6M1013-22 T3-0268 B

Turbochar urbochar ed model

M

Water coolin s stem

F

High speed 4-stroke 4-stroke

10

Upgrade number

6

Number of cylinders: cylinder s: 6

13

Stroke: 130mm

22

10X horsepower

T3

Euro-III model

0268 Ordering number

LG958L is equipped with Dalian Deutz BF6M1013-22T3 engine. 1KW=1.36HP

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2. Introduction of Main Parameters

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Engine type

6-cylinder, inline, water-cooled, turbocharged and inter-cooled, direct injection, and ω-shaped combustion chamber

Minimum idling speed rpm

600

Engine power (kw)

169

Compression ratio

18:1

Fuel type

Diesel

Cylinder pressure bar

30-38

Engine rated speed

2200 r/min

Working sequence of cylinders

1-5-3-6-2-4

Cylinder bore/ stroke

108/130mm

Fuel injection pump

Electronically controlled monoblock pump

Minimum fuel consumption

≤210g/kW•h

Fuel injector

Opening pressure of 210230bar

Oil cooling mode

Recirculating water cooled

Thermostat opening temperature

83

Displacement

7.146

Thermostat full open temperature

95

Rotation direction

Counter-clockwise, when observed towards flywheel

Cylinder sleeve type

Wet cylinder sleeve


II. Product Characteristics

1. The monoblock pump structure adopted is proved by European market for 12 years, featuring good product continuity and stable performance. The electronically controlled monoblock pump is directly arranged on the cylinder block and is directly driven by camshaft so that the high pressure is established instantly within the pump. The short high pressure oil pipes feature universality and easy repair.

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2.

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With compact structure and small volume, it’s lighter by 100~150kg compared with like products and features simple structure and easy repair as the repair and maintenance points are arranged on the same side of the engine.


3.

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With minimum fuel consumption under full load in the world’s leading level, it’s lower by 5g/KWh and saves fuel by 3~5L per 100km compared with like products. RELIABILITY IN ACTION

Ambient noise curve of engines from industry benchmark competitors

Ambient noise curve of BF6M1013 engine

4.

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The engine adopts monoblock pump structure, which is located within the cylinder block and is directly driven by the camshaft. With good rigidity and low noise (only 96dB under full load), it’s the model with lowest noise among the domestic industry benchmark competitors. Internal noise of cab: The internal noise meets the standard ISO 6396 and is comparable with passenger cars. RELIABILITY IN ACTION

5. The parts feature good universality, high serialization level, and easy matching of complete vehicle. The oil sump adopts symmetric design so that positions can be swapped. The water pump and fan are separated against mutual interference. There are multiple arrangement schemes available for the turbocharger, such as middle upward arrangement, middle downward arrangement, and rear arrangement, depending on the user’s needs.

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Section II Basic Structural Principle of DDE Engine I. Engine Block Group

The engine block group includes cylinder block, cylinder sleeve, cylinder head, valve chamber cover cap, and oil sump. Function of engine block group: The engine block is the primary assembly structure for engine. It bears the moving parts of the engine and the internal and external acting forces during the working of the engine and is fitted with all kinds of accessories. Therefore, the engine block must have enough strength to bear all kinds of acting forces under rated load or even a certain overload. It must have enough strength to minimize the deformations of all parts during the working of engine and have good anti-corrosion performance against coolant, lubricating oil, and flammable gas. 10


1. Cylinder head

The DDE engine cylinder head adopts integral structure. The cylinder head is installed on the top of the cylinder block to seal the cylinder from the top and constitute the com ust on c am er. s t comes nto requent contact w t g temperature an g pressure combusted gas, the cylinder head is subject to high thermal load and mechanical load. The cylinder head is also fitted with intake and exhaust valve seats and valve pipe bore for installation of intake and exhaust valves and intake and exhaust pipelines. The cylinder is fixed onto the cylinder block by 18 bolts (for 4-cylinder engines) and 26 bolts (for 6-cylinder engines). The cylinder head bolts must be tightened as per specified sequence, in order to ensure the uniform force application on the cylinder head. Before tightening the cylinder head bolts, apply engine oil onto the threaded parts. Tightening torque for cylinder head bolts: 30N.m for 1 step, 80N.m for 2 step, and 90º angle for final step. 11


Intake valve Exhaust valve Intake manifold

Exhaust manifold

The cylinder head is cast with intake and exhaust ports, of which the intake ports are connected with intake pipes and the exhaust ports are connected with exhaust pipes. The intake and exhaust valve for every cylinder can be determined depending on the positions of the intake and exhaust ports.

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2. Cylinder block The engine block is the basic framework for the engine. It not only bears the acting force of high pressure and high temperature gas, but also it's fitted with almost all engine parts. Therefore, the cylinder block must have sufficient strength and rigidity. (1) Depending the different mounting planes of the cylinder block and oil sump, the cylinder block is commonly classified into following three types: k c o l b r e d n i l y c l a r e n e G

k c o l

k c o l

r e d n i l y c y r t n a G

r e d n i l y c l e n n u T

The DDE engine adopts gantry cylinder block.

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(2) Advantages of DDE cylinder block

The DDE cylinder block adopts German standard high strength gray cast iron. With integral noise and vibration reduction design, it reduces the noise by 3dB(A) compared with like products. The design of cylinder block takes the easy repair and maintenance into sufficient consideration. It’s built through best optimized design via finite element method. The cylinder block is cast with low pressure fuel line, which is functioned as fuel inlet line of monoblock pump for non-electronically controlled engine and as fuel return line of monoblock pump for electronically controlled engine, to achieve more reasonable layout of complete unit, prevent leakage, and preheat the fuel. The design of cylinder block takes the easy repair and maintenance into sufficient consideration so that all external accessories, except the starter and turbocharger, are arranged on the same side of the engine.

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(3) Structure Structure of cylinder block

This place is the fuel line on the cylinder block and is the fuel return line of monoblock pump for electronically controlled engine.

1. Cylinder block 2. Main bearing bolts 3. Locating pin 4. Screw plug 5. Sealing gasket 6. Screw plug 7. Screw plug 8. Screw plug 9. Bushing 10. Bushing 11. Water jacket plug 13. Screw plug 14. Guide bushing 23. Guide bushing 24. Screw plug

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The 1013 main oil line regulator valve is installed on the lower plane of the cylinder block. To replace the regulator valve, tap a threaded hole with M8 screw tap and screw in puller to take out the regulator valve at the time of disassembly. There is an opening extent of regulator valve valve when no engine oil pressure is available. available. The higher the engine oil pressure is, the larger the opening extent is. 16


3. Cylinder sleeve The cylinder structure in which the cylinder is directly bored in the cylinder block is referred to integral cylinder. The integral cylinder features good strength and rigidity and is capable of bearing high load. However, the integral cylinder features high material requirements and high cost. If the cylinder is manufactured into independent cylindrical parts (namely cylinder sleeve) and then installed into cylinder block. (1) Classification of cylinder sleeve For water-cooled engines, depending on whether the cylinder sleeve comes into contact with coolant, the cylinder sleeve is classified into dry type and wet type. Characteristics Characteristics of dry type cylinder sleeve: block, its outer walls do not come into contact with the coolant directly. Instead, its outer walls come into direct contact with the walls of cylinder block, with thin wall thickness (generally 1~3mm). It features the adv advan anta tage gess of integ integra rall cylind cylinder er bloc block, k, na name mely ly good good strength ngth and rigid igidit ityy. Howe Howeve verr, the the mach machiinin ning is rela elativ tively ely comp compli lica cate ted d, as the the fini finissh mach achinin ining g is requi equirred for for both both inne innerr an and d oute outerr surf surfac aces es,, an and d it brings about inconvenient disassembly and assembly and poor heat radiation. 17


Characteristics of wet type cylinder sleeve: After the cylinder sleeve is installed into the cylinder block, its outer walls come into direct contact with the coolant and the cylinder sleeve only comes into contact with the cylinder block by a belt on the top and bottom respectively, with the wall thickness generally at 5~9mm. It features good heat radiation, uniform cooling, and easy machining. Generally, the finish machining is required only for inner surface and no machining is required for the outer surface coming into contact with the coolant, featuring easy disassembly and assembly. However, its disadvantages include lower strength and rigidity against dry type cylinder sleeve and easy occurrence of water leakage. Therefore, some leak-proof measures shall be taken. e eng ne tte on a opts wet type cy n er s eeve. (2) Measures for wear reduction of cylinder sleeve Correct start and startup. At the cold start of diesel engine, rotate the engine for several times to lubricate the friction surfaces before start. Then, idle run the engine for warm-up and do not depress the throttle pedal. Do not start up the machine when the coolant temperature is less than 40ºC. During the running, try to maintain the diesel engine within normal temperature range and travel at moderate speed. Correct choice and use of lubricating oil. Choose the lubricating oil with best viscosity depending on the seasons and performance requirements of diesel engine. Enhance the maintenance works for fuel filter, oil filter, and air cleaner to minimize the ingress of mechanical impurity into the cylinder.

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4. Cylinder gasket

(1)

The cylinder gasket is installed between cylinder head and cylinder block and is functioned to seal the contact surface between cylinder head and cylinder block , , . , of piston crown and cylinder block is generally 1±0.1mm and can be adjusted by adding or removing cylinder gasket.

(2)

Structure characteristics: The material of cylinder gasket must have certain elasticity to compensate the unevenness of the fitting surface and ensure the sealing. In addition, the cylinder gasket must have good heat resistance and pressure resistance against ablation and deformation under high temperature and high pressure. At present, the copper sheet – cotton structure cylinder gasket is mostly applied. Some engines adopt the cylinder gasket with woven wire net or perforated steel plate framework and asbestos and rubber adhesive pressed on both sides.

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(3) Calculation method for thickness of cylinder gasket for DDE engine The DDE engine adopts metal cylinder gasket, which is classified into three thickness classes identified by the number of bores at the edge of the cylinder gasket. To choose appropriate cylinder gasket, it’s required to measure the piston protrusion. Based on the maximum measurement of piston protrusion, choose the cylinder gasket of corresponding thickness.

Piston protrusion

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gasket

[0.280.54mm

one bore

[0.540.64mm

two bores

[0.640.75mm

Three bores


Measurement method for piston protrusion

[1] Remove the oil dirt from the surfaces of cylinder block, place the measurement bar and cushion block on the sealing surface of crankcase, on which the cylinder sleeve is installed, and set the pointer of dial gauge to mark “0”.

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[2] Place the dial gauge and measurement tool at the measuring points of piston, rotate the engine to move upward the piston, and observe the variation of dial gauge pointer. When the pointer reaches maximum reading and starts to reduce, stop the rotation of engine and read the reading of the dial gauge. In such case, the reading is the piston production. [3] At the time of measurement, choose the Ø95mm circle on the piston as the measuring point and keep the measuring point consistent with the direction of piston pin. All pistons shall be measured and the maximum value shall be chosen.

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The height difference between the cylinder block plane and the piston crown is used as the basis to determine the thickness of the cylinder gasket. At the replacement of piston, measure the value of each piston in turn. Take the cylinder gasket thickness S as per the diagram above. At the time of measurement, the piston must at the absolute top dead center. The height difference between cylinder gasket plane and piston crown = ②-① (The range of top gap ① is 0.9~1.1mm.)

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5. Oil sump

The oil sump of DDE engine adopts symmetric design to ensure easy installation. Two oil drainage plugs are fitted to ensure easy oil drainage, as the oil can be drained from both left and right sides. With the application of really low force, the oil sump is generally is stamped from thin steel sheet and its shape depends on the overall arrangement of the engine and the capacity of the engine oil. The oil drainage plug is fitted on the bottom of the oil sump. Generally, the oil drainage plug is fitted with permanent magnet to absorb the metal particles from the lubricating oil and reduce the engine wear. The gasket is fitted on between upper and lower crankcase fitting surfaces to prevent the leakage of lubricating oil.

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5. Gear chamber cover

DEUTZ engine adopts the design thinking of separated gear chamber cover (including rear oil seal) and flywheel housing. The flywheel housing is functioned for connection with complete vehicle and the gear chamber cover is functioned to seal the gear chamber and prevent the leakage of engine oil and is also functioned for ventilation of crankcase. This structure greatly reduces the weight and types of flywheel housing and feature good universality. The flywheel housing is fitted with two locating sleeves (21) for orientation purpose at the installation of gear chamber cover.

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II. Crank-link mechanism 1. Brief

The crank-link mechanism is the main part for the engine to generate and output the power. Function: It converts the force applied by the combusted gas onto the piston crown to the torque of crankshaft and outputs the mechanical energy. Structure: It’s composed of the piston rod group and crankshaft flywheel group. Crankshaft and main bushing: The DEUTZ engine adopts fully balanced cast steel crankshaft, with full support. 26


2. Piston rod group Piston pin Circlip

Connecting rod bearing bushing cap Bolt

Piston ring Piston

Rod

Rod bushing

The piston rod group includes piston, piston rings, piston pin, rod, and rod crankshaft. Function: It transmits the power acquired from the combustion process to the crankshaft.

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(1) Piston top surface Flywheel end mark

Printed drawing number

Weight group mark team A

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weight of the piston(g) (986

994]

，

B

(994,1002]

C

(1002,1010]

Printed manufacture date The manufacture date is in format of “Year-Month-Day” year 2001

code 1

year 2013

code D

month 1

2002

2

2014

E

2

B

2003

3

2015

F

3

C

2004

4

2016

G

4

D

2005

5

2017

H

5

E

2006

6

2018

J

6

F

2007

7

2019

K

7

G

2008

8

2020

L

8

H

2009

9

2021

M

9

G

2010

A

2022

N

10

K

2011

B

2023

P

11

L

2012

C

2024

R

12

M


code A

(2) Piston rings

The piston rings include the 1 compression ring, 2 compression ring, and oil control ring in turn from the top to bottom. Two compression rings are mainly functioned to seal the cylinder and the oil control ring is only functioned to uniformly apply the lubricating oil to the cylinder walls for lubrication during the vertical movement of the piston and at the same time scrape the excessive lubricating oil into the oil sump. 29


Two compression rings have the directionality. During the installation, the compression ring marked with “top” shall face towards the piston crown. During the installation, the openings of three piston rings shall stagger for a certain angle with each other and shall avoid the �45º range in the direction of the piston pin.

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(3) Connecting rod The mass of the connecting rod assembly (connecting rod, connecting rod small end bushing, and connecting rod bolts) shall be controlled within 1865~1965g. The connecting rod assembly is grouped by mass into 10 groups, with the mass difference no more than 10g between any two neighboring groups. Group mark A B C D E

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Mass (g) 1865~1875 1875~1885 1885~1895 1895~1905 1905~1915

Group mark F G H I J

Mass (g) 1915~1925 1925~1935 1935~1945 1945~1955 1955~1965


(3) Precautions for assembly of connecting rod

(1) The fracture-splitting process is adopted for the parting surface of connecting rod body cap. The fracturesplitting surface shall be free of cracking or loose metal particles. It's disallowed to reversely install the connecting rod body and cap, or it will impair the indented junction surface. (2) While assembling the connecting rod, the boss on the connecting rod shall face towards the flywheel end. (3) The connecting rod is stamped with number. During the assembly, pay attention to align properly to prevent reverse installation. Once reversely installed, the indented junction surface will be impaired. (4) There is a boss on one end of the connecting rod bushing. During the assembly, align with the bushing cap to prevent reverse installation.

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3. Crankshaft flywheel group (1) Brief

Connecting rod journal

Counterbalance

Main journal

Crankshaft flange c F r r a o n n k t s o h a f f t

c R r a e n a k r s o h f a f t

Connecting rod journal lubricating orifice

Main journal Lubricating orifice

Crankshaft gear

The crankshaft flywheel group includes the crankshaft, flywheel, and all parts installed on the crankshaft (crankshaft timing gear, bushing, thrust plate, and pulley). Function: It transmits the power to the engine oil pump, water pump, air compressor, fuel pump, fan impellor, and flywheel and outputs the power.

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Crankshaft and main bushing: The DEUTZ engine adopts fully balanced cast steel crankshaft, with full support.

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(2) Precautions for Assembly

[1] There are total 7 crankshaft bushing caps, which are marked with numbers 1, 2, 3, 4, 5, 6, and 7 respectively counting from the flywheel end. Pay attention to the sequence and do not wrongly install at the time of installation.

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[2] The crankcase is fitted with guide posts to ensure the smooth installation of crankshaft bushing caps.

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[3] The crankshaft bushing caps are fitted with reverse installation proof boss so that the caps can’t be properly assembled once reversely installed.


[4] The 2nd crankshaft bushing cap is fitted with 2 pairs of thrust plates (total 4 plates) to prevent the axial runout of crankshaft. The axial runout range of crankshaft is 0.1~0.3mm. At the installation of the thrust plates, the oil line shall face towards the crankshaft. The other two thrust plates shall be installed on the crankshaft in spacing of 180º from the above two thrust plates.

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Pay attention to prevent reverse installation

Oil groove

[5] There are two oil grooves on the crankshaft bushings so that the lubricating oil lubricates the bushings via oil grooves. While installing the bushings, pay attention to align the external boss of bushing with the bushing cap to prevent the reverse installation.

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[6] During the installation of engine oil pump, pay attention to correspond the key within engine oil pump to the key slot of the crankshaft and keep level the mounting plane of engine oil pump with the cylinder block plane.

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[7] While assembling the crankshaft, align the timing mark on the crankshaft gear with the timing mark on the camshaft. The timing mark of camshaft is on the top of camshaft gear and the timing mark of crankshaft is at the tooth space of the crankshaft gear. When it’s properly timed, the tooth top with timing mark is engaged with the tooth space with timing mark.

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III. Valve mechanism

1. Brief The rocker subassembly of engine is mainly composed of tappets, push rods, intake and exhaust valves, and rockers.

1. Push rod 2. Tappet 3. Rocker fastening bolts 4. Rocker seat 5. Rocker 7. Washer 8. Retainer 9. Fastening nut 10. Adjustment screw 11. Rocker group 12. Rocker seat 13. Spring 14. Washer 15. Intake valve 16. Exhaust valve 17. Spring seat 18. Valve pipe 19. Intake valve seat 20. Exhaust valve seat 41


2. Camshaft

1. Camshaft 2. Camshaft bushing 3. Sensing pin 4. Camshaft gear 5. Bushing 6. Idler . .

The valve tappets of the Deutz engine are directly driven by camshaft and the camshaft also drives the monoblock pump. The camshaft of Deutz engine is fully supported. The BF6M engine is fitted with 6+1 bushings and BF4M engine is fitted with 4+1 bushings. All bushings are same, except the bushing near the flywheel end. 42


3. Main parts

a ve

Intake manifold and preheating plug 43

Tappet RELIABILITY IN ACTION

4. Arrangement of valves

The cylinder at the flywheel end is the 1 cylinder and there are 1 cylinder exhaust valve, 1 cylinder intake valve, 2 cylinder exhaust valve, 2 cylinder intake valve, 3 cylinder exhaust valve, 3 cylinder intake valve, 4 cylinder exhaust valve, 4 cylinder intake valve, 5 cylinder exhaust valve, 5 cylinder intake valve, 6 cylinder exhaust valve, and 6 cylinder intake valve in turn from left to right. As the engine equipped on 958L incorporates the EGR function, while adjusting the valve clearance, it’s necessary to find out the compression top dead center for valve adjustment cylinder by cylinder. The intake valve clearance is 0.3mm and the exhaust valve clearance is 0.5mm.

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IV. Fuel System 1. Brief The fuel line pressure measuring point for low pressure chamber shall be the downstream of fine filter outlet. The fuel pressure shall be 4.2bar at 1,500~1,899rpm, 5bar at 1,900~2,300rpm, and 5bar at 2,300rpm. When measured at the cylinder block outlet, the measurement shall be lower than normal pressure by 1bar. When measured at inlet of fuel delivery pump, the fuel pressure shall be no higher than -0.3bar. The temperature of return fuel shall not exceed 80ºC and the amount of return fuel shall be more than 8L. 1. Fuel tank 2. Fuel line to diesel pump 3. Diesel pump 4. Fuel line to diesel filter . ese er 6. Fuel line to fuel injection pump 7. Fuel injection pump 8. Fuel line to fuel injector 9. Fuel injector 10. Fuel return pipe 11. Fuel pipe bolt with pressure control valve 12. Fuel line of fuel return tank 13. This distance shall be as large as possible.

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Fuel operation diagram

Fuel tank

Fuel-water separator

Fuel delivery pump

Fuel fine filter

Monoblock pump

Fuel injector

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2. Main parts

Fuel deliver

um

Electronically controlled monoblock pump 47

Fuel injector RELIABILITY IN ACTION

3. Low pressure fuel line

The diesel from the diesel tank flows to the fuel delivery pump via fuel-water separator and, after being filtered by diesel filter, flows via external connector into the metal low pressure fuel line that is connected with the electronically controlled monoblock pump. Each pump is connected with external fuel inlet pipe separately. The fuel return passage is cast on the cylinder block. As the fuel supply amount of the fuel delivery pump is more than 10 times of the fuel outlet amount of the monoblock pump, a great amount of excessive fuel flows back to the diesel tank via fuel return check valve and return pipe to completely bleed the air from the fuel line by a great amount of returning fuel and radiate the monoblock pump by a great amount of returning fuel flowing through the monoblock pump. 48


3. High pressure fuel line

The fuel in the low pressure fuel line enters into the monoblock pump. Under the action of the monoblock pump, the high pressure fuel is formed from the monoblock pump to the fuel injector via really short high pressure fuel pipe. When the pressure reaches 220bar, the fuel injector opens to inject the atomized fuel into the combustion chamber, which mixes with the air to form flammable air mixture.

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4. Electronically controlled monoblock pump (1) Brief Advantages: The monoblock pump is one of the latest technologies, which ensures that the combustion is more adaptable to the needs of working condition to achieve more sufficient combustion and higher efficiency and lower the exhaust contamination and fuel consumption. It also boast following advantages: Compact structure and good rigidity, as it’s directly driven  by camshaft via tappets. Up to 1,600bar fuel injection pressure.  Smaller installation space.  Short and standardized hi h ressure fuel i e.  Good and freely adjustable speed regulation performance  and applicability for engines of different applications.  Easy replacement of pump. Function: Under different working conditions of the engine, it supplies high pressure fuel at fixed timing and fixed quantity as per the requirements of complete unit so that all cylinders can function normally to output the required power and torque and at the same time meet the emission standard. It plays a vital role for the performance, working reliability, and durability of the engine and is the core part of the fuel supply system.

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(2) Working Principle Injection module

When the solenoid valve is cut off, the fuel return passage opens and the monoblock pump can’t establish high pressure. The fuel return passage closes and the fuel pressure can rise rapidly only when the solenoid valve is turned on. The high pressure fuel flows into the fuel injector through a really short high pressure fuel pipe for fuel injection. When the solenoid valve is cut off, the fuel return passage opens for rapid pressure relief and the fuel injection is stopped. The power-on duration of the solenoid valve determines the recirculating fuel supply amount. The working process of electronically controlled monoblock pump is mainly classified into four stages: fuel injection process, bypass process, injection process, and unloading process.

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[1] Fuel suction process: The solenoid valve is not powered on. When the plunger moves downward, the fuel pressure within the pump chamber is less than the fuel pressure of low pressure fuel line. In such case, the fuel of low pressure system enters into the high pressure injection system via the fuel inlet on the plunger sleeve.

[2] Bypass process: When the plunger moves upward, the fuel in the plunger chamber is compressed. However, if the solenoid valve is still under cut-off state, the fuel pressure within the plunger chamber depends on the opening pressure of the fuel return check valve, which is far lower than the opening pressure of fuel injector, so that the fuel will return to the fuel tank via fuel return passage.

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[3] Fuel injection process: During the fuel supply stroke of the plunger, when the electronic control issues the fuel injection control pulse at a specific moment, based on the sensor signals collected, and powers on the electromagnet via drive circuit. In such case, the fuel inlet and return passages are closed and an enclosed volume is formed within the plunger chamber. Following the rise of the plunger, the fuel within the enclosed volume is compressed and the pressure rises rapidly. When the pressure is higher than the opening pressure of the fuel injector, the needle valve opens and the fuel is injected into the cylinder. Note: The resistance of the solenoid coil for the solenoid valve of monoblock valve is approximate 0.9Ω. If less than 0.4Ω, the coil is probably short circuited. The fuel injection timing is controlled by the power-on moment and the fuel injection amount is calculated by the power-on duration to realize the control of fuel injection amount.

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[4] Unloading process: When the control pulse is terminated, the electromagnet is cut off and the fuel return passage opens so that the fuel overflows via fuel return passage, the high pressure fuel unloads to the low pressure system via valve ort, and the ressure of hi h pressure fuel line drops. When the pressure drops to the opening pressure of needle valve, the fuel injection is completed.

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V. Cooling system 1. Brief

(1) The integral cooling system is adopted, featuring compact structure and easy installation. (2) High reliability and low operation cost. (3) High cooling efficiency and low required power (4) 1.5bar pressure in cooling system after the running of engine. The antifreeze must be used as the normal coolant temperature is above 100ºC. In addition, as the thinnest cast thickness of engine block water passage is only 4mm, the use of antifreeze can prevent he blockage of water passage due to water scale. 55


2. Thermostat

The thermostat is functioned to change the recirculation strength of the water (route and flow rate) depending on the engine load and water temperature. In addition, it can shorten the hot start time of engine and reduce the fuel consumption and wear of engine parts. The DDE engine adopts paraffin thermostat, with opening temperature at 83ºC and full opening temperature at 95ºC.

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(1) Minor recirculation

Before the hot start of the cold engine, the water temperature is below 83ºC. In such case, the main valve closes and the bypass valve opens so that the coolant can directly flow back to the water inlet of water pump via bypass pipe and is compressed into the water jacket by the water pump. In such case, the water only recirculates in a small scale between water jacket and water pump without flowing through the radiator. In such case, as the cooling strength is low, the water temperature can rise rapidly to ensure that all parts of the engine can warm up uniformly and rapidly or prevent the under-cooling of the engine. Due to short flow route and low flow rate of the coolant, this recirculation is referred to as minor recirculation, namely thermostat  water pump  engine radiator  water jacket  thermostat.

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(2) Major recirculation

When the water temperature within the engine rises to 95ºC, the main valve opens fully and the bypass valve fully closes so that the coolant flows completely into the radiator. In such case, the cooling strength is increased to drive down the water temperature or keep it from being too high. In such case, as the coolant flow route is long with high flow rate, it’s referred to as major recirculation, namely thermostat water pump engine oil radiator water jacket radiator thermostat. When the coolant within the engine is between two above-mentioned temperatures, both the main valve and bypass valve partially opens so that the major recirculation and minor recirculation of coolant coexist. In such case, the coolant recirculation is referred to as mixed recirculation.

→

→

58

→

→

→


(3) Major and minor recirculation routes

59


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VI. Lubrication System 1. Brief Structure of lubrication system: Oil sump, engine oil pump, engine oil radiator, engine oil filter, pressure limiting valve, main oil passage, and engine oil pump suction pipe. Function of lubrication system: The lubrication system is functioned to continually convey a sufficient amount of clean engine oil at appropriate temperature to the friction surfaces of all drive parts during the running of friction, in order to reduce the friction resistance, lower the power consumption, and relieve the wear of engine parts and promote the working reliability and durability of the engine. Lubrication mode: Pressure lubrication, splash lubrication, and lubrication by lubricating grease. Functions of lubricating oil: Lubrication, cooling, cleaning, sealing, and rusting-proof.

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Diagram of lubricating oil circuit

1. Oil sump 2. Intake manifold 3. Engine oil pump 3a. Oil return valve 3b. Relief valve 4. Engine oil radiator 4b. Engine oil radiator bypass valve 5. Engine oil filter 6. Main oil line 7. Main bearing 8. Connecting rod bearing 9. Camshaft bearing 10. Oil passage to fuel injector orifice 11. Fuel injection orifice for cooling of piston 12. Tappet control orifice for rocker pulse 13. Push rod 14. Rocker 15. Oil return passage to oil sump 16. Engine oil sensor 17. Oil passage to exhaust turbocharger 18. Exhaust turbocharger 19. Oil passage to compressor or hydraulic pump 20. Compressor 21. Hydraulic pump 22. Oil return passage of compressor or hydraulic pump 23. To oil sump 24. From turbocharger to crankcase

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2. Engine oil pump DEUTZ engine oil pump is of rotor type. Installed within front hood of engine and directly driven by crankshaft, it features as below:  Installed within front hood to ease the disassembly.  Directly driven by crankshaft, without additional drive parts.  Small installation space.  Large diameter, more teeth, and stable oil supply of pump.  The rotor of oil pump is installed onto the crankshaft by three unevenly distributed keys and the pumped oil amount is controlled by the tooth width of oil pump rotor. The oil supply amount of the oil pump is 50L/min for 4-cylinder engine and 75L/min for 6-cylinder engine. The oil supply amount is 90L/min for oil delivery pump of BF6M1013ECP. Upon detection of low engine oil pressure during normal running of vehicle, check the engine oil pump. Upon detection of clear internal wear or scratch, replace the engine oil pump.

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Oil pressure chamber

Oil suction chamber

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Oil inlet


3. Engine oil radiator

Radiator

Radiator cap

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The engine oil radiator is built in the coolant circuit and is under series connection on the upstream of the main oil line to control the temperature of lubricating oil by means of the temperature of coolant. As the coolant temperature can be controlled automatically, the engine oil temperature can a so e con ro e o a cer a n ex en . Therefore, the engine oil temperature can be controlled within normal range. When the engine oil temperature is high, the engine oil is cooled by the coolant. When the oil temperature is low at the start and warm-up of the engine, the engine oil absorbs heat from the coolant to rapidly increase the engine oil temperature, lower the flow resistance, and help the lubrication. RELIABILITY IN ACTION

4. Route of lubricating oil Fan end

Engine oil filter

radiator

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1. Oil sump 2. Engine oil radiator bypass valve 3. Engine oil filter bypass valve . 5. Engine oil pump 6. Supercharger 7. Main oil passage pressure limiting valve


1 4

7 2

6

3

5

8

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Route of lubricating oil circuit

Lubricating oil from engine oil pump Oil passage 3

Oil passage 1 Main Oil passage 4

Oil passage 2

Radiator

Engine oil filter element

Oil passage 5, for lubrication of camshaft

Oil assa e 6 for lubrication of crankshaft and oil passage 7 for lubrication of connecting rod and piston

8

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Oil passage for tappet and push rod

Rocker


VII. Electronic control system 1. Composition of electronic control system

Sensor

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Electronic control unit (ECU) Electronically controlled monoblock pump


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2. Sensors (1) In the level of complete unit, ensure that the crankshaft sensor, camshaft sensor, and engine oil pressure sensor work normally, or the complete unit can’t be started.

Crankshaft speed sensor

Turbocharge d air pressure sensor

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Camshaft speed sensor

Engine oil pressure sensor

Air pressure sensor, within ECU

Turbocharge d air temperature sensor

Fuel Coolant temperat temperature ure sensor sensor

Throttle pedal position sensor


(2) Function of camshaft speed sensor:

The crankshaft sensor needs 15s to find out the top .

At the time of start, the determination of the 1 cylinder compression top dead center can be taken as the reserved function of crankshaft speed sensor. 73


(3) Crankshaft speed sensor

The crankshaft speed sensor is installed on the front of the engine. By measuring the tooth signal on the engine flywheel, it provides instant speed of engine to the ECU for accurate timing and fuel amount control on the engine.

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(4) Fuel temperature/water temperature sensor

The water temperature/fuel temperature sensor provides the engine coolant/fuel temperature signal to the ECU and its sensing unit is a negative temperature coefficient thermistor. The ECU continually collects the real-time water temperature and fuel temperature to correct the fuel injection amount.

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(4) Fuel temperature/water temperature sensor

The intake pressure temperature sensor provides to the ECU the intake temperature and intake pressure information at the downstream of enginecooler. The pressure sensing unit is a silicone diaphragm and the temperature sensing unit is a negative temperature coefficient thermistor. The ECU collects the intake pressure and temperature information to correct the fuel injection amount. 76

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(5) Engine oil pressure sensor

This sensor real-time detects the engine oil pressure information and transmits to the ECU. When the engine oil pressure is out of normal range, the ECU will restrain the engine power or control the flameout of the engine.

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3. Main functions of ECU

(1) Start control For an engine, to ensure the start reliability and start smoke number emission requirements, the fuel injection timing and start torque must be set as per the method below: Fuel injection timing = f (speed, fuel injection amount, and coolant temperature) Start torque = f (speed, coolant temperature, and start time). The start control function is under activated state, till the engine speed exceeds the start end speed and the engine enters idling control. The driver can operate the engine only under the idling control state. The start end speed is subject to the coolant temperature and atmospheric pressure. 78


(2) Fuel injection timing adjustment The adjustment of fuel injection timing is intended to meet the emission regulations and fuel economy requirements as well as consider the cold start and low noise. The adjustment of fuel injection timing is related to the engine performance and additional correction. Fuel injection timing = f (speed, fuel injection amount, cooling temperature, intake pressure, and atmospheric pressure) (3) Malfunction Diagnosis The electronic control unit incorporates the real-time self-diagnosis function. Upon detection of malfunction, the ECU will save the malfunction information and current environmental information into the ECU. At the same time, the malfunction indicator lamp on the instrument panel flashes to remind the driver of getting repaired by the service station. At the service station, the repair personnel will connect special diagnostic tool to the ECU and read out the malfunction information.

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(4) Cold start auxiliary control Under cold temperature, to improve the cold start performance of the engine, the ECU will determine whether the intake preheating is required and the required preheating duration depending on the current engine temperature, which is realized through the control on the intake preheating relay. (5) Engine protection function It’s intended to protect the engine under certain extreme conditions. Under the working conditions such as over-high coolant temperature and under-low engine oil pressure, the engine power will be lowered or it will even lead to engine flameout, in order to protect the engine.

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Section III Cause Judgment and Troubleshooting for Common Malfunctions of Engine System I. Diagnosis and troubleshooting procedure for malfunctions of DDE engine

1. Thoroughly consider the malfunction cause by considering the engine as an integral unit. 2. Thoroughly understand the information from the operator: Abnormal noise, working condition and environment, change of oil pressure or water temperature, abnormal dust or smoke at occurrence of malfunction, consumptions of engine oil, fuel, and coolant and their recent changes, smoke density, fuel in use, presence of engine surge during idling or full speed running, presence of long-term idling, recent temporary repair and repair information, previous occurrence of similar malfunction, information of part replacement, and status after previous treatment.

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3. Conduct necessary checking: Engine cleanliness, belt tension, presence of external leakage of engine oil, fuel, or water, levels of engine oil, water, and fuel, engine sound, presence of jitter, and presence of smell, carbon deposit, oil mud, and other abnormality beneath the roc er cap at t e t me o disassembly. 4. Conduct correct analysis. 5. Conduct correct repairs. 6. Verify whether the repairs fulfilled actually solve the malfunction.

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II. Diagnosis and troubleshooting principle for malfunctions of engine

1. Upon detection of malfunction, firstly check whether the operation and 2.

3. 4. 5.

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substituting the maintenance with repair. Poorly manufactured parts (such as hollow filter element), especially the counterfeit products procured due to temptation of cheap prices, will greatly shorten the service life of diesel engine. At the occurrence of malfunction, exclude one by one from simpleness to difficulty. Do not replace any part easily before the malfunction cause is found. Pay attention to disconnect the battery during repair, in order to prevent the start of engine. RELIABILITY IN ACTION

III. Analysis of malfunction cases 1. Cause for difficult start or start failure (1) Malfunction of starter electric lock (2) The temperature is less than start limit temperature (3) Malfunction of starter interlock (4) Blockage of fuel delivery pump inlet passage (5) Working failure of cooling fan/broken or loose belt (belt-driven fuel delivery pump) (6) Battery depletion or malfunction

(7) Loose or oxidized wires of starter motor

8 Dama e or en a ement failure of starter motor (9) Incorrect valve clearance

(10) Leakage of high pressure fuel pipe

(11) Malfunction of preheating plug

(12) Damage of fuel injector

(13) Air content in diesel system

(14) Dirty diesel filter and diesel strainer

(15) Incorrect engine oil grade or viscosity

(16) Disqualified diesel

(16) No signal from sensor to ECU

(18) Malfunction of starter relay

(19) ECU malfunction

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[1] Functional block diagram of starter system

Function block diagram of system

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[2] Fuel line judgment Malfunction symptom: While driving the rotation rotation of engine with starter, starter, there is no exhaust gas or start symptom of the engine. Judgment method: Cylinder interruption interruption method. 1. Outflow of diesel: It indicates that the malfunction occurs at the high pressure fuel line. 2. Air in out-flown diesel: The malfunction occurs in low pressure fuel line or fuel return line. 3. No outflow of diesel: The malfunction occurs at low pressure fuel line.

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No outflow of diesel after cylinder interruption

p L r e e s a s k u a r g e e u o e f l o l l i n w e

O b a s m e r o v e n f t u e l

Repair

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B l o c k e d

Check fan belt

A d j u s t i f l o o s e

R e p l a c e i b r o k e n

N o r m a l

Check fuel delivery pump pulley

R e p l a c e i f n o r o t a t i o n

N o r m a l


Check fuel delivery pump

L o w f u e l s u p p l y o f f u e l d e l i v e r y p u m p

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P r e s s u r e o f m a n u a l f u e l s u p p l y

Outflow of fuel after cylinder interruption

C h e c k a n a d j u s t r e g u l a t o r v a l v e

W e a r o h o u s i n g

No pressure

S o f t c h e c k v a l v e s p r i n g

S t a g n a t i o n f f u e l r e t u r n c h e c k v a l v e


B r o k e n h e c k v a l v e s p r i n g

II. Unstable running or start failure (1) Working failure of cooling fan/broken or loose belt (belt-driven fuel delivery pump) (2) Incorrect valve clearance (3) Leakage of high pressure fuel pipe (4) Damage of fuel injector (5) Air content in diesel system (7) Disqualified diesel (8) ECU malfunction (9) Malfunction of speed sensor

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III. Insufficient engine power (1) Check the maximum idling speed with speedometer Depending on the configuration of the engine, the maximum idling speed shall be higher than the rated speed by 6~8%. The basic calculation equation is as below: Maximum idling speed = Rated speed × 1.07 If the maximum idling speed is insufficient, check whether the throttle pedal can reach the maximum throttle position. (2) Check the fuel injector for presence of leak through or cavitation due to insufficient primary fuel line pressure. (3) Check the low pressure fuel line system. The insufficient pressure of low pressure . The minimum fuel supply pressure of low pressure fuel line in 5bar system (unloaded): 1500-1899/min >4.2bar

1900-2500/min > 5.0bar

>2500/min >5.3bar The pressure measuring point of the low pressure fuel line shall be the downstream of the fuel outlet of the fine filter (namely at the fuel inlet of crankcase). If no measurement space is available in this point, measure at the upstream of the fuel return valve (namely at the fuel outlet of the crankcase). Caution: Under rated speed, the pressure measured at the fuel outlet of crankcase is lower than the fuel pressure at fuel inlet of crankcase by approximate 1.0bar. 90


Causes for insufficient pressure of low pressure fuel line: - Blockage of fuel strainer and fine filter. - Failure of fuel return valve. - Over-high flow resistance in fuel delivery pipeline from fuel tank to fuel delivery pump. - Sufficient fuel supply pressure in fuel delivery pump. - Excessive flow resistance in fuel delivery pipeline from fuel return valve to fuel tank. In event of excessive resistance, the fuel return amount will be insufficient and the fuel temperature will rise (the fuel temperature shall not exceed 80ºC).

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Checking Method: (1) Provided that the filter element is not blocked, if the fuel pressure can’t be reached, check or replace fuel return valve. (2) If the pressure is still insufficient, check the fuel delivery line for presence of over-high flow resistance. Method: Supply the fuel on the upstream of fuel delivery pump directly with a fuel barrel, in order to determine the over-high resistance due to fuel supply pipeline and strainer from the fuel tank to fuel delivery pump. delivery pump shall be no less than 12mm and the fuel pressure at the inlet of fuel delivery pump during the maximum idling speed shall be more than 0.5bar (or -0.35bar for Euro-II compliant engines). (3) If the pressure is still insufficient, check the fuel return amount. Method: Disassemble the fuel return end of the fuel return pipe from the fuel tank and insert into an empty barrel. Measure the fuel return amount of the engine under the maximum idling speed for 1min. The amount shall be above 8L.

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IV. Black smoke Root cause: Due to incomplete combustion of diesel, the incompletely combusted carbon forms free carbon, which is floating within the combusted gas and is exhausted along with the exhaust gas to form black smoke. Malfunction Cause: (1) Blockage of air cleaner and excessive intake resistance. 

(3) (4) (5) (6) (7)

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pump or over-high uneven fuel supply among cylinders. Blockage of inter-cooler. Poor injection of fuel injector Low cylinder pressure. Poor quality of diesel. Insufficient cylinder pressure.


Diagnosis and troubleshooting method for black smoke: (1) Disassemble the air cleaner and check and clean the inter-cooler. If the black smoke of diesel engine disappears, it indicates that the air cleaner is too dirty and shall be cleaned. (2) If the air cleaner is normal and the black smoke is present during idling of the diesel engine, it indicates excessive fuel supply amount under idling condition. Check the fuel injection pump. (3) If the fuel supply of the fuel injection pump is normal, check the fuel supply . (4) If the fuel supply timing is correct, check the working condition of cylinders by single cylinder interruption method. If the speed variation is not obvious and the black smoke symptom disappears after the fuel interruption of certain cylinder, it indicates the poor working of this cylinder, probably the excessive fuel supply amount of branch pump, poor mist injection quality of fuel injector, or under-low cylinder pressure. After the cause is determined, resolve the cause. (5) If no problem is detected in above-mentioned items, the diesel quality is probably too bad, which leads to incomplete combustion. Replace the diesel.

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V. White smoke 1. Cause: The diesel within the combustion chamber is vaporized and not combusted and is drained in milk white from the exhaust pipe or the water content in the diesel is vaporized in the cylinder to form steam, which is exhausted in white from the exhaust pipe. Malfunction Cause (1) Water content in diesel or water leakage due to burst cylinder gasket or cracked cylinder head or cylinder block, leading to water ingress of cylinder. ow cy n er pressure. (3) Under-low working temperature. (4) Poor injection quality of fuel injector. (5) Poor diesel quality. (6) Late fuel supply moment of fuel injection pump.

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Diagnosis and troubleshooting method for while smoke: (1) During the running of diesel engine, loosen the air bleeding screw or high pressure fuel pipe connector on the monoblock pump and check the fuel flow for presence of water drops. IF no water drop is present, it indicates that the white smoke in exhaust pipe is caused by the water content in diesel. Fully drain the water from fuel tank, diesel filter, and high and low pressure fuel lines. (2) If there is no water in diesel, open the water tank and observe the water tank for presence of air bubble. If the air bubble is present, it indicates the ingress of coolant into the cylinder. Disassemble the cylinder head, find out the malfunction portion, and repair or replace. (3) If there is no ingress of water into cylinder, check the cylinder pressure. If the cylinder pressure s too ow, c ec an repa r. (4) While traveling in winter, if the diesel engine is frequently working under low temperature, it will lead to presence of white smoke in exhaust pipe. Check whether the shutters are closed securely and the insulation sleeve is good. Otherwise, the repair is required. (5) If no problem is detected in above-mentioned items, check the fuel injection quality of the fuel injector. (6) If the fuel injection quality meets the requirements, check the fuel supply timing and adjust as specified. The diesel quality is of certain influence on the white smoke of diesel engine exhaust pipe. If necessary, replace with new fuel for comparison testing.

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VI. Blue smoke A great amount of engine oil that enters into the combustion chamber is vaporized to oil gas and exhausted from exhaust pipe before being combusted. Malfunction Cause: (1) Excessive engine oil in oil sump. (2) Penetration of engine oil into combustion chamber due to damaged oil seal of turbocharger. (3) Serious permeation of engine oil in cylinder. (4) Wear of valve stem and pipe, leading to excessive gap and failure of valve pipe seal.

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Diagnosis and troubleshooting method for blue smoke: (1) Check the engine oil level in oil sump. If above specified level, drain the excessive engine oil. (2) If the engine oil level is normal, disassemble the fuel injector and check the oil dirt and carbon deposit of the fuel injector. In event of serious oil dirt and carbon deposit, it indicates the serious permeation of engine oil on cylinder or excessive gap of valve stem and pipe. Disassemble the cylinder head to find out the cause and resolve the malfunction. (3) Check the working status of seal rings of intake and exhaust valve pipes. 4 Check the sealin status of turbochar er.

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VII. Engine oil pressure warning

Step 1

Check the oil sump for under-low (over-high) oil level or shortage of oil and check for qualified engine oil trademark. 

Step 2 Check the engine oil filter and cooler for excessive resistance. Step 3

Check for over-high water temperature of cooling system and check for over-high engine oil temperature.

Step 4

ec ur oc arger, s ra ner, eng ne o p pe ne, an connec or gas e or presence of blockage or rupture.

Step 5

Check the pressure limiting valve of main oil line for excessive or insufficient adjustment.

Check the bushings for excessive gap or damage, check whether the engine Step 6 working hours reach the overhaul period, and check the parts for serious wear.

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VIII. Over-high water temperature The water temperature is high when the diesel engine runs under high load. Step 1 Check whether the oil sump level, water tank level, and water pump belt are normal. Step 2 Check whether the thermostat and connecting water pipes are normal. Step 3

Check the water temperature gauge and water temperature sensor for normal functioning.

Step 4

The checking of fan found out that the external surfaces of the water tank are .

IX. Oil-water mixture 1. Damage of engine oil radiator sealing gasket or engine oil radiator. 2. Damage of cylinder gasket. 3. Cracking and blister of cylinder block.

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LG958L Training Material Chapter III Engine: Tuesday, May 19, 2015

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