What Causes Oil Leakage from the Cylinder Head of a Car Engine?
2 Answers
Oil leakage from the cylinder head of a car engine may be caused by a leaking valve cover gasket, oil leakage at the engine timing cover, a loose or damaged oil drain plug at the oil pan, poor sealing due to a long-unreplaced drain plug gasket, a leaking oil filter, oil leakage from the engine oil pan, or a leaking crankshaft oil seal. Below are methods to address oil leakage between the cylinder head and cylinder block: 1. Valve cover leakage. If the leakage is due to poor sealing of the valve cover, the valve cover gasket needs to be replaced. 2. Oil leakage at the engine timing cover. Remove the engine timing cover and reapply sealant. 3. Loose or damaged oil drain plug at the oil pan. Tighten or replace the drain plug. 4. Poor sealing due to a long-unreplaced drain plug gasket. Replace the gasket, and it is recommended to replace this gasket regularly according to the maintenance cycle. 5. Oil filter leakage. If the oil filter is installed too loosely or too tightly, or if a low-quality oil filter is used, replace it with a new one. 6. Oil leakage from the engine oil pan or cylinder block cracking. If the oil pan gasket is aged, remove the oil pan, replace the gasket, and reapply sealant. 7. Crankshaft oil seal leakage. Replace the crankshaft oil seal.
I just encountered an engine oil leakage issue last month. The leakage usually occurs at the cylinder head seal, mainly due to aging seals or loose bolts. After several years of driving, the cylinder gasket tends to dry out and harden, and the engine's thermal expansion and contraction can cause oil to seep out. If the bolts aren't tightened properly, they can also loosen over time and lead to oil leaks. Additionally, when the oil is overfilled, the high pressure can force oil out through the gaps. Ignoring it can waste oil, increase the risk of engine overheating, and even lead to more serious failures. So after noticing signs of oil leakage, I immediately drove to a nearby repair shop to check the seals and tighten the bolts. Now the car runs much smoother. Regularly inspecting the seal condition during maintenance can prevent such troubles.
