Cooling system malfunctions (Opel Astra H)

33. Overheating

1. The coolant level has dropped.

2. The water pump drive belt is worn or damaged, or its tension adjustment is incorrect

3. The internal channels of the radiator are blocked or the radiator grille is dirty (blocked).

4. Thermostat is faulty

5. The fan impeller blades are broken or cracked.

6. The fan switch sensor is faulty.

7. The coolant temperature gauge is faulty.

8. The water pump is faulty

34. The coolant does not reach operating temperatures

1. The thermostat is faulty.

2. The coolant temperature gauge readings are inaccurate.

3. The fan switch sensor is faulty.

35. External coolant leaks

1. The hoses are damaged or destroyed as a result of aging of the material, or their fastening on the fittings has become loose.

(Text copied from an online resource: «OpelBook.ru»)

2. The water pump seals are damaged - coolant leaks through the inspection hole in the pump body.

3. There are leaks from the internal channels of the radiator or reservoir.

4. There are leaks through the engine drain plug or the release plugs of the water galleries.

36. Internal coolant leaks

Note: Internal coolant leaks are usually detected by checking the engine oil. Inspect the dipstick blade and the inside surfaces of the cylinder head(s) for traces of water and oil foaming.

1. There are leaks through the cylinder head gasket - check the cooling system under pressure.



2. There are cracks in the cylinder walls or in the head casting.

37. Coolant loss occurs

1. There is too much coolant in the system.

2. The coolant boils away as a result of engine overheating.

3. There are internal or external coolant leaks

38. Coolant circulation is disrupted

1. The water pump is not functioning properly. The easiest way to check that the pump is functioning is to pinch the upper radiator hose while the engine is idling. If you feel a jolt of fluid inside the hose when you release it, the pump is functioning properly

2. The cooling system is clogged - flush it and fill it with fresh fluid. If necessary, remove the radiator and perform a reverse-flow flush

3. The water pump drive belt is worn or damaged, or its tension is not adjusted correctly.

4. Thermostat is stuck.