What are the reasons for engine oil mixing into the radiator in older model Cruze?
2 Answers
The main reasons for engine oil mixing into the radiator in older model Cruze can be attributed to three factors. Below is an explanation of these causes: Cylinder liner damage: The presence of engine oil in the radiator may be due to cracks in the cylinder liner. Under high-pressure conditions, engine oil can seep directly into the car's radiator through these gaps. Radiator damage: Damage to the engine oil cooler or transmission oil cooler can also result in engine oil mixing into the radiator, which requires inspection. Cylinder head gasket damage: If there is engine oil in the radiator and the high-temperature warning light is also illuminated, it is highly likely due to a damaged cylinder head gasket. Prolonged exposure of the cylinder to high-pressure fuel conditions can lead to cylinder liner damage.
I've encountered this issue several times. The most common reason for oil mixing into the coolant reservoir in old Cruze models is a blown head gasket. Especially for vehicles over eight years old, after several instances of engine overheating, the sealing gasket at the junction between the cylinder block and cylinder head can burn through. Like milk foam in coffee, engine oil slowly seeps into the cooling system. Some repair shops take the easy way out by simply replacing the head gasket, but it's important to remind the mechanic to use a feeler gauge to check the cylinder head's flatness. I've seen cases where new gaskets started leaking again after just three months because the warped cylinder head wasn't properly addressed. Another hidden issue is the transmission oil cooler leak. This component is integrated with the radiator, and if the internal oil lines crack, automatic transmission fluid can also mix in, producing a particularly strong burnt smell.
