- White or milky-looking coolant
- A drop in coolant level
- Overheating engine
- Rough idling
- Misfires
- Exhaust smoke
2. Damaged oil cooler: The oil cooler is a small radiator that helps to keep the engine oil cool. If the oil cooler is damaged, it can leak oil into the coolant system. This can cause similar symptoms to a blown head gasket.
3. Cracked cylinder head: A cracked cylinder head can also allow oil to leak into the coolant system. This is a rare occurrence, but it can happen if the engine has been overheated or otherwise damaged.
4. Faulty oil filter: A faulty or damaged oil filter can allow oil to bypass the filter and leak into the coolant system.
5. Water pump seal failure: A failed water pump seal can allow coolant to leak into the engine oil. This can also cause the oil to appear milky or white.