How to Fix a Leaky Valve Cover Gasket

Step 1: Assess your engine type and gather tools and materials

If you could look inside the valve cover on the top of your running engine, you’d see a whole lot of oil splashing around. The valve cover catches that oil and sends it back into the engine. But over time, valve cover gaskets shrink, harden and start leaking oil. On a V-type engine, the leaking oil usually just drips down the side of the engine (and onto your driveway) and turns into black muck. But on a four-cylinder engine, it can actually leak into the spark plug tubes and cause misfires. Replacing the gaskets on a V-type engine is a job for the pros. But you can replace the gasket on a four-cylinder engine in about an hour and for less than $25. Here’s how to do it.

Pick up a new valve cover gasket kit, a tube of room temperature vulcanizing (RTV) sealant and a spray can of brake cleaner. You’ll need ordinary metric sockets, a plastic putty knife and a torque wrench.

Step 2: Remove the leaky valve cover

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Photo 1: Tap the cover loose

Remove the bolts and tap around the valve cover with a soft-faced mallet to break it loose. Never pry with metal tools—they can gouge the aluminum cylinder head and cause permanent leaks.

Start the job by removing the decorative plastic cover on the top of the engine (if equipped). Next, remove (and label) any hoses, cables and electrical connectors that attach to the valve cover. Then remove the spark plugs.

If you see any oil pooling in the spark plug tubes, clean it out with a rag wrapped around a screwdriver. Get out as much gunk as you can and then remove and, if necessary, replace the spark plugs with new ones before proceeding. Once the new plugs are in, remove the valve cover hold-down bolts, noting the length and location of each bolt. Then break the valve cover loose and lift it off the engine (Photo 1).

Step 3: Replace the old gasket

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Photo 2: Install the new gasket

Seal the timing cover joint with a small bead of RTV. Then install the valve cover and torque the bolts to specifications.

Peel off the old gasket and clean the valve cover with brake cleaner and clean rags. Next, clean the gasket mating surfaces on the engine. Use the plastic putty knife (never metal) to remove any traces of old RTV from the timing belt cover-to-cylinder head. Catch the old RTV with a rag so it doesn’t fall into the engine. Once the cover and mating surfaces are clean and dry, apply new RTV in the same locations and install the new gasket (Photo 2). Valve cover gaskets are designed to seal “dry,” so don’t apply sealant to the face of the gasket.

Finish off the job by snugging up the valve cover bolts to the torque specifications in your shop manual. Keep in mind that valve cover bolt specs are usually shown in inch/lbs., not foot/ lbs. To convert inch/lbs. to foot/lbs., simply divide by 12.

Reinstall all the cables, hoses, ignition components and electrical connectors and fire it up.