Common Failure of Yuchai 4D24/4D24T Engine Turbocharger

Intake system blocked

Check the pipes between air filter and compressor, the compressor outlet, intake pipes, and intake manifold, clean all.

Intake leakage

Check leakage of the pipes between air filter and compressor, the pipes between compressor outlet and inlet, connection between intake manifold and engine. Tighten bolts, replace gaskets and other parts if necessary.

Exhaust system blocked

Repair or replace related parts

Exhaust leakage

Check connections of exhaust manifold and diesel engine, inlet of turbo and exhaust manifold, turbo housing and intermediate housing, turbo outlet and exhaust manifold, replace the gasket if leakage, tighten the bolts.

Compressor rotor interference with compressor housing body or turbo housing

Replace assembly

Inlet or return oil pipe leakage

Replace

Fuel quality does not meet the requirements:

1. Use incorrect grade of fuel;

2. Excessive fuel impurities;

3. Excessive water in fuel.

Replace by qualified fuel, and clean fuel circuit

Fault code in ECU memory:

1. Fault codes can be read through the diagnostic apparatus;

2. Fault flash codes can be read through  diagnostic request switch;

3. Electronic control system fault information can be read through CAN meter

1. If the fault code or fault flash code

information clearly points to a specific electronic control components, inspect

and repair the corresponding faults of sensors, actuators and its line;

2. If read fuel volume slip ring control model related fault codes or fault flash codes information, focus on investigation fuel related failures according to the subsequent steps;

3. After repairs, use the diagnostic apparatus or diagnostic request switch to delete the fault history information, and fully running engine to confirm ECU memory without fault code information.

Fuel running out

Check, add, and remove the air from the fuel circuit

Ignition switch circuit failure

Check the machinery ignition switch circuit

Battery power supply to the ECU, voltage too low, interrupt or open circuit

Check battery terminals, fuses and related circuits

Crankshaft sensor and its circuit fault

1. Check crankshaft sensor connector and circuit;

2. Check whether installation clearance between crankshaft sensor and the signal panel is installed correctly;

3. Check whether the crankshaft sensor is dirt or damage.

Low pressure fuel circuit failure

1. Make sure there is enough diesel in the tank;

2. Discharge of air in low pressure fuel circuit;

3. Check the pipes, the joint tightening

condition, and, whether the hose and the joint are affected by extrusion, damage, or the diameter is not correct;

4. Check whether the fuel filter,

pre-filter are blocked or damaged;

5. Check whether the fuel tank ventilation device is blocked or contaminated   (open tank cover and check pumping sound);

6. Check whether the fuel pump and the inlet & outlet of filter are connected incorrectly;

7. Check whether transfer pump is failure.

Injector fault

1. Check injector atomizing;

2. Check injector shim thickness correct or not;

3. Check injector protrusion height correct or not.

High-pressure fuel pump failure:

1. Fuel channel blocked in high-pressure fuel pump;

2. High-pressure fuel pump plunger wear;

3. Relief valve of high-pressure pump blocked, contaminated or stuck.

Clean or replace the high-pressure pump, replacement of clean fuel, full road test.

Diesel engine lubricating oil path is not smooth, cause bearing wear.

If the water temperature is normal and engine sudden stop, most of such case belong to this situation, should open the oil pan inspection, maintenance, replacement of damaged parts corresponding.

Diesel engine overheated and scuffing, generally due to water shortage or water temperature is too high

Let the engine self-cooling (not allowed to fill the cold water or flush with cold water), and then try to rotate the crankshaft, if there is no stuck, can be added with cooling water and then start engine. If crankshaft cannot be rotated regular, engine should be disassembled,

inspected, repaired, replaced damaged parts.

Diesel engine ECU failure

Replace ECU

Internal damage of diesel engine

Check and replace damaged parts at the service station

Ignition switch circuit failure

Check the machinery ignition switch circuit

Battery power supply to the ECU, voltage abnormal or interrupt

Check whether the battery terminals and related circuits are not in contact

Crankshaft sensor and its circuit fault

1. Check crankshaft sensor connector and circuit:

2. Check whether installation clearance between crankshaft sensor and the signal panel is installed correctly;

3. Check whether the crankshaft sensor is dirt or damage.

Low pressure fuel circuit failure

1. Make sure there is enough diesel in the tank;

2. Elimination of air in low pressure fuel circuit;

3. Check the pipes, the joint tightening

condition, and, whether the hose and the joint are affected by extrusion,

damage, or the diameter is not correct;

4. Check whether the fuel filter, pre-filter are blocked or damaged;

5. Check whether the fuel tank ventilation device is blocked or contaminated   (open tank cover and check pumping sound);

6. Check whether the fuel pump and the inlet & outlet of filter are connected incorrectly;

7. Check whether transfer pump is failure.

Injector fault

1. Check injector atomizing;

2. Check injector shim thickness correct or not;

3. Check injector protrusion height correct or not.

Pressure temperature sensor or circuit fault

Check the pressure temperature sensor and its line on the intake manifold, and monitor the value of the intake pressure signal by the diagnostic instrument to see whether it is lower than the actual value.

Cooling water temperature sensor or circuit fault

Check the cooling water temperature sensor and its circuit, through the diagnostic instrument monitoring the temperature signal value to see if lower than the actual value; dismantle the coolant temperature sensor connector if necessary, and start engine to compare

Engine mounting bolts loose, shock pad damaged, the power transmission system is not align

Fastening bolts, replace shock pad, realign

Intake system blockage or leakage

Check whether the air filter or intake pipes is blocked or leaked

Turbocharger damaged or surge

Replace the turbocharger, check the working conditions and whether intake pipes are blocked.

Accessories failure

Check the fan, alternator, belt, bracket, whether interfere or damage, etc.

Diesel engine ECU failure

Replace ECU

Internal damage of diesel engine

Check and replace damaged parts at the service station

Crankshaft sensor and its circuit fault

Check crankshaft sensor connector and circuit;

2. Check whether installation clearance between crankshaft sensor and the signal panel is installed correctly;

3. Check whether the crankshaft sensor is dirt or damage.

Low pressure fuel circuit failure

1. Make sure there is enough fuel in the tank;

2. Elimination of air in low pressure fuel circuit;

3. Check the pipes, the joint tightening

condition, and, whether the hose and the joint are affected by extrusion,

damage, or the diameter is not correct;

4. Check whether the fuel filter, pre-filter are blocked or damaged;

5. Check whether the fuel tank ventilation device is blocked or contaminated   (open tank cover and check pumping sound);

6. Check whether the fuel pump and the inlet & outlet of filter are connected incorrectly;

7. Check whether transfer pump is failure.

Injector fault

1. Check injector atomizing;

2. Check injector shim thickness correct or not;

3. Check injector protrusion height correct or not.

Shock pad damage

Check shock pad

Vehicle speed sensor and its circuit fault

Check vehicle speed sensor and its circuit fault

Intake system blockage or leakage

Check whether the air filter or intake pipes is blocked or leaked.

Valve leakage or abnormal lash

Check and adjust the valve seal and valve clearance.

Internal damage of diesel engine

Analyze the oil and check the oil filter to determine the potential damage.

Injector sealing problems

1. Injector mounting hole gland damage cause leakage;

2. Injector leak in the cylinder head

Cylinder head crack

Replace

Fuel pump seal not well

Replace fuel seal

Injector O ring damaged

Check the O ring.

Diagnostic request button is turned on

Disconnect the diagnostic request button.

Fault code in ECU memory:

1. Fault codes can be read through the diagnostic instrument;

2. Fault flash codes can be read through diagnostic request button;

3. Electronic control system fault information can be read through CAN meter

1. If the fault code or fault flash code information clearly points to a specific electronic control components, inspect and repair the corresponding faults of sensors, actuators and its line;

2. After repairs, use the diagnostic instrument or diagnostic request button to   delete the fault history information, and fully running engine to confirm ECU memory without fault code information.