Symptoms
- Oily residue or drips along the upper sides of the engine, below the valve cover
- Burning oil smell if drips reach the exhaust manifold below
- Oil level drops slowly over time
- Sometimes visible oil pooling in the small recessed areas of the valve cover itself
Likely causes
- CommonHardened or cracked valve cover gasketRubber or cork gaskets harden and shrink with heat and age, eventually letting oil seep past the seal.
- PossibleWarped valve coverA cover that's slightly bent (from over-tightening bolts or age) won't seal evenly even with a new gasket.
- PossibleLoose or uneven valve cover boltsBolts that aren't torqued evenly can leave gaps in the seal even with a good gasket.
What to do
- Clean the top and sides of the engine with degreaser to remove old oil residue and make new leaks easier to spot.
- Drive the car a short distance, then inspect the valve cover edges closely for fresh oil seeping out.
- Check that valve cover bolts are snug (without over-tightening, which can warp the cover) if a recent gasket job was done.
- Replace the valve cover gasket if confirmed as the source, following the correct bolt tightening sequence and torque spec.
- Inspect the valve cover itself for warping if a new gasket doesn't stop the leak, since a warped cover may need replacement or resurfacing.
Tools and parts
- Degreaser
- Torque wrench
- Basic socket set
Valve cover gasket for your engineSearch: “valve cover gasket”
When to call a pro
See a mechanic if the valve cover is hard to access due to other engine components in the way, or if a new gasket doesn't stop the leak, suggesting a warped cover.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.