The purpose of your 1994 Toyota Corolla's valve cover gasket is to keep your engine's oil contained. If you notice that oil is leaking from your engine, you may have a faulty valve cover gasket. This typically begins to happen after the 100,000 mile range, although you may want to change your valve cover gasket before such leaks even begin. Since replacing the valve cover gasket is a relatively simply project, your best bet is to change the gasket as a preventative measure, rather than waiting for oil to leak and an engine repair bill to ensue.
Unclamp the black (negative) battery cable from your battery terminal.
Disconnect the spark plug wires, which are the blue, red and black wires located at the top of your Corolla's engine.
Remove both tube brackets and the vent hose from over your engine. These parts should all slide off easily using your fingers.
Remove the exhaust gas recirculation (EGR) valve. You should not need any tools to unscrew the valve, as it will turn much like a bottle cap.
Loosen the valve cover bolts using your wrench.
Lift the valve cover straight upward and set it aside.
Peel the old valve cover gasket off. You can use your flat-head screwdriver to remove any stubborn chunks of foam that may remain on the gasket seat.
Wipe the valve cover and the valve cover seat clean using your shop rag and degreaser.
Peel the backing off the new valve cover gasket and orient it so that the sticky side is face down.
Place the new gasket directly onto the perimeter of the valve cover.
Press on the gasket firmly to ensure that it is stuck securely to the gasket seat.
Replace the valve cover and fasten the bolts using your socket wrench.
Replace the hoses, EGR valve and tube brackets by hand.
Reconnect the spark plug wires into the same places they were originally plugged.
Replace the negative (black) battery cable by clamping it back onto the battery.
Add your motor oil slowly, one quart at a time, until you can see the fluid nearing the top of the motor oil fill port. If you replaced the gasket as a preventative measure, this step may not be necessary. However, if your engine was leaking fluid prior to the gasket change, you will need to replenish your motor oil.
Close your hood and your Corolla's valve cover gasket replacement is finished.
