De12ti двигатель руководство по ремонту

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© Copyright 2023. Все права защищены. DSEngine. Developed By Alex

DE12, DE12T &

DE12TI & DE12TIS

DIESEL ENGINE

Shop Manual

65.99892-8030B

Daewoo reserves the right to improve our products in a continuing process to provide the best possible product to the market place. These improvements can be implemented at any time with no obligation to change materials on previously sold products. It is recommended that consumers periodically contact their distributors for recent documentation on purchased equipment.

This documentation may include attachments and optional equipment that is not available in your machine’s package. Please call your distributor for additional items that you may require.

Illustrations used throughout this manual are used only as a representation of the actual piece of equipment, and may vary from the actual item.

1. General information

1.1. Engine characteristics

1.1.1.OMEGA combustion bowl

The OMEGA combustion bowl is a unit designed to perform high-efficiency, lowemission combustion. As the rim around the combustion bowl port of the upper of the piston has been machined in a smaller size than the interior of the combustion bowl, strong swirl is produced in the combustion bowl and strong squish flow makes the fuel be mixed more sufficiently with air.

Due to the application of OMEGA combustion system and optimal ultilization of intake and exhaust port configuration within the cylinder head, the DE12 series engines discharge a very low level of hazardous exhaust gases such as smoke, nitrogen oxide, hydrocarbon, or carbon monoxide and thus ensure high performance and low fuel consumption.

EA2M1001

<Figure. 1-1> OMEGA combustion bowl

1.1.2.Wastegated turbocharging system

1)What is the wastegated turbocharging system?

Turbocharger is a system designed to pressurize the intake air to increase engine output and decrease fuel consumption by using the energy of exhaust gas discharged from the engine. However, the turbocharger has a weak point at low engine speed, its performance may drop, thus performance at low speed is relatively low.

The WASTEGATED TURBOCHARGING SYSTEM is an up-to-date turbocharging system remedying such a defect, and the working principle is as follows:

A small-sized high performance turbine is used to improve engine performance at low speeds. As high charging efficiency can be obtained even If a small amount of exhaust gas is present at low speed. On the other hand, if higher charging pressure is produced than what is present at high speed, fuel consumption increases. To correct this, part of exhaust gas is forced to be discharged into the exhaust manifold through the waste gate, not through the turbine.

The waste gate is controlled by the ACTUATOR mounted in the turbocharger, and if the pressure in the turbocharger becomes higher than what is required for the engine, the waste gate is forced to open.

2)DE12T, DE12TI and DE12TIS engines are featured by the application of turbochager so that the torque in low speeds can be increased by 30% or more, not only to create high performance, just from the time of starting off the vehicle but also to greatly reduce fuel consumption.

Compressed air outlet por

Turbine

Intake air

Exhaust gas outlet port

Waste gate

Compressor

Actuator

<Figure 1-3> Turbochager

1.2. Main data and specifications

1.4. Engine performance curve

1.4.1. DE12

Output(ps)

EQM1004I

Output(ps)

EQM1005I

Output(ps)

EQM1006I

Output(ps)

EQM1007I

Output(ps)

EQM1008I

Output(ps)

EQM1009I

Power output(ps)

Revolution(rpm)

EA2M1002

1.5. Exterior view of engine

1.5.1. DE12for Bus

EQM1010I

1.5.2. DE12for Truck

24

11

7

16

2. Major maintenance

2.1. Preventive maintenance

2.1.1.Cooling water

1)Check the coolant level of the radiator by removing the radiator filler cap, and add coolant if necessary.

2)Check the pressure valve opening pressure using a radiator cap tester. Replace the radiator filler cap assembly if the measured value does not reach the specified limit.

3)When injecting antifreeze solution, first drain out the old coolant from the cylinder block and radiator, and then clean them with cleaning solution.

4)Be sure to mix soft water with antifreeze solution .

5)A proportion of antifreeze is represented as the ratio of antifreeze in volume, and antifreeze must be added according to each ambient temperature as described below:

CAUTION

If you add antifreeze in excess of 50% in volume, the engine may be overheated. Avoid this.

As the individual freezing points corresponding to the above proportions of antifreeze are subject to change slightly according to the kind of antifreeze, you must follow the specifications provided by the antifreeze manufacturer.

6)When the ratio of antifreeze in the mixture decreases new coolant should be added to make up for the loss in old coolant resulting from engine operation, check the mix ratio with every replenishment of coolant, and top up as necessary.

7)To prevent corrosion or air bubbles in the coolant path, be sure to add a specific additive, i.e. corrosion inhibitor, to the coolant.

•Type : DAC65L

•Mix ratio : 1.5M of inhibitor to 50M of coolant

(Namely, add corrosion inhibitor amounting to 3% of water capacity.)

Add antifreeze of at least 5% in volume to prevent possible engine corrosion in hot weather.

2.1.2.Fan belt

1)Use a fan belt of specified dimensions, and replace if damaged, frayed, or deteriorated.

2)Check the fan belt for belt tension. If belt tension is lower than the specified limit, adjust the tension by relocating the alternator and air conditioner. (Specified deflection: 10~15mm when pressed down with thumb)

2.1.3.Engine oil

1)Check oil level using the oil dipstick and replenish if necessary.

2)Check the oil level with the vehicle stationary on a level ground, engine cooled. The oil level must be between MAX and MIN lines on the stick.

3)Engine oil should be changed at the specified intervals. Oil in the oil filter also should be changed simultaneously.

(First oil change : 1,000km running)

• Suggested engines oils

2.1.4.Oil filter

1)Check for oil pressure and oil leaks, and repair or replace the oil filter if necessary.

2)Change the oil filter element simultaneously at every replacement of engine oil.

2.1.5.Fuel filter

1)Drain water in cartridge with losen the cock under filter from time to time.

2)The fuel filter should be replaced at every 20,000km

2.1.6.Air cleaner

1)Replace any deformed or broken element or cracked air cleaner.

2)Clean or replace the element at regular intervals

2.1.7.Valve clearance

1)Turn the crank shaft so that the piston in No. 1 cylinder reaches the TDC on compression

stroke, then adjust the valve clearance.

2)After releasing the lock nut for the rocker arm adjusting screw, insert a feeler gauge of specified thickness into the clearance between the rocker arm and valve stem, and adjust the clearance with the adjusting screw. Fully tighten the lock nut when a correct adjustment is obtained.

3)Carry out the same adjusting operation according to the firing order(1-5-3-6-2-4) (Valve clearance(with engine cooled): 0.30mm for both intake and exhaust)

2.1.8.Cylinder compression pressure

1)Stop the engine after warming up, then remove the nozzle holder assembly.

2)Install a special tool(gauge adapter) in nozzle holder hole and mount the compression gauge in position of the nozzle holder.

3)Cut off fuel circulation, rotate the starter, then measure compression pressure in each cylinder.

6Testing conditions: Coolant temperature 20C, Engine speed, 200 rpm (10 turns)

2.1.9.Injection nozzle

1)Assemble a nozzle to a nozzle tester.

2)Check injection pressure, and adjust the nozzle using the adjusting shim if the pressure does not meet the specified limit.

3)Check nozzle spray patterns and replace if damaged.

EFM1006I

<Figure 2-1> Nozzle spray patterns

2.1.10.Fuel injection pump

1)Check the fuel injection pump housing for cracks or breaks, and replace if damaged.

2)Check and see if the lead seal for idling control and speed control levers have not been removed.

2.1.11.Battery

1)Check the battery for damage or leaking of battery fluid(electrolyte) from cracks on the battery. Replace the battery if damaged.

2)Check battery fluid level and add distilled water if necessary.

3)Measure the specific gravity of the electrolyte in the battery. Recharge the battery if the hydrometer readings are lower than the specified limit(1.12~1.28)

2.2. Diagnostics and trouble shooting for the engine

2.2.1. Diagnostics

1. Engine won’t start