Valve Cover Gasket
Just imagine the kind of environment the valve cover gasket is exposed to right under the hood! It will come as no surprise why, after some time, this sturdy mechanical seal will wear out and go brittle. Once it has come to this, pressure that's maintained between the valve cover and the engine block will be lost. You may notice any of the following symptoms of a bad valve cover gasket:
- Oil leak
- Oil seepage
- Engine smoke
The broken valve cover gasket isn't at all a big problem, but this can reach a critical point if this goes unchecked and is left untreated. The simple oil leak can turn into a more serious case, which might require engine reconstruction or complex repair. As oil level in the engine drops fast, the drivetrain may perform poorly. This may result in light troubles to serious engine damage. Once the symptoms are there, you have to peek under the hood and check the gasket to see if it's shot and needs to be replaced. Do this right away before the problem becomes too severe to tackle. Changing the gasket isn't that difficult, though in some vehicles, you may have to remove other parts that get in the way.
Changing a valve cover gasket
Step 1: Find the bolts that hold down the cover. Once you have a good visual of the cover and its bolts, use a right-size wrench or socket to remove these fasteners. Be careful not to strip the heads. If they're a bit stuck or difficult to remove, use some penetrating oil on them or a spray of rust remover.
Step 2: Lift the cover and pull it out after the bolts had been removed. If the cover is stuck, the valve cover gasket might still be clinging on to the original seal. What you can do here is use a putty knife. Slip it under the corners until the cover lifts and pops off. You may tap the knife's end using a hammer to work your way through. If there's a gap or a loose corner, slip in a flathead screwdriver to pry off the cover. Another thing you can do is to break the seal by tapping one of the corners of the cover with a rubber mallet. Just be sure not to bend the corner or dent the cover because of too much force.
Step 3: Use a putty knife or razor blade for scraping off the gasket sealer. With sandpaper, smooth out the mating surface by sanding it. The surface should be free of bumps.
Step 4: Cover the parts of the engine that are left open after the cover had been removed. You may use paper towels or clean rags. Also sand the mating surface and clean it, same thing with the cover.
Step 5: Dab some gasket sealer on the engine's mating surface. This should cover the whole surface and should be about 1/8-inch thick. Remove excess sealer around the edges by wiping this off. Let the sealer get slightly sticky before you fit in the new valve cover gasket, lined up with the holes on the engine block.
Step 6: Add a thin layer of sealer on the gasket's top side. The excess sealer should be removed. Let it settle for a while until it's tacky.
Step 7: Set the valve cover onto the gasket. Place the cover carefully, making sure that the sealer won't be ruined.
Step 8: Prepare the hold down bolts. They should first be sprayed or soaked with WD-40 before you secure the cover with these fasteners. Tighten these bolts according to the torque specs, in a crisscross pattern.
Step 9: Remove any remaining gasket material on the lower parts of the gasket area. After everything is set, you can now test the newly installed valve cover gasket. Drive your vehicle for a few minutes and then check for leaks after you turn it off. Place a dry paper towel underneath the gasket area to see if there'll be drips of oil coming from the block. If there's a leak, you may have to adjust the bolts and tighten them down evenly according to specs. Also check if the reinstalled cover is flush or placed properly or if there are still bits of gasket material or some debris on the valve cover or the engine mating surface that have to be removed.