Why Does the Valve Cover Gasket Keep Leaking Oil After Replacement?
2 Answers
The reasons for continued oil leakage after replacing the valve cover gasket include the following: 1. The crankcase forced ventilation valve is blocked, causing increased crankcase pressure, which then releases through the valve cover gasket or other weak points, resulting in oil leakage. 2. The valve cover gasket has aged, leading to poor sealing. 3. If the crankcase ventilation valve is clogged, or if the piston rings and cylinder wall gaps are too large, causing excessive blow-by gas, the high crankcase pressure will force gas to escape through weak sealing points, such as the valve cover gasket or front/rear crankshaft oil seals, resulting in engine oil leakage.
My previous car had a similar issue. After replacing the valve cover gasket, it leaked oil even worse. Later, I found out it was because the gasket wasn't installed properly—uneven or overly tight screws can deform it. Over time, the engine base may warp slightly, and if the new gasket doesn't fit snugly, it won't seal properly. Make sure the cleaning job is thorough; leftover oil residue has a big impact. DIYers often overlook details, so it's best to have a professional shop handle it. Also, part quality is crucial—cheap gaskets use inferior materials that degrade and shrink under high heat. Ignoring this can lead to oil buildup corroding engine parts and higher repair costs. Regular maintenance can prevent such headaches. After installing a new gasket, drive a short distance and recheck the tightness to ensure everything's secure.
