Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Engine Cooling System: Operation: Diesel
| 1 - COOLANT RECOVERY PRESSURE CONTAINER |
| 2 - PRESSURE CAP |
| 3 - HEATER CORE |
| 4 - AUXILIARY HEATER |
| 5 - ENGINE |
| 6 - OIL COOLER |
| 7 - WATER PUMP |
| 8 - THERMOSTAT HOUSING |
| 9 - RADIATOR |
| 10 - COOLANT DRAIN VALVE |
| 11 - SERVICE FILL VENT VALVE |
The water pump draws coolant from the radiator and delivers it to the engine block. The coolant travels through the engine block into the cylinder head. Coolant exits the engine at the thermostat. If the coolant temperature is less than 87°C (189°F) the thermostat directs all of the coolant back to the water pump. If the coolant temperature is between 87°C (189°F) and 102°C (216°F) the thermostat is in the mix mode and directs the coolant to the radiator and the water pump. If the coolant is greater than 102°C (216°F), the thermostat directs all of the coolant to the radiator.
The thermostat also feeds excess coolant and bleeds air from the system through a hose leading to the coolant reservoir. The reservoir returns coolant to the inlet side of the water pump. A port and hose at the rear of the engine block provides coolant to the heater core. This coolant is returned to the engine at the intake side of the water pump.
The oil cooler receives coolant directly from the engine block. A hose returns this coolant to the inlet side of the water pump.
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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