As our Zetec engines get up there in miles and age, the valve cover gasket loses its elasicity and turns into a harder, brittle plastic type compound. Particularly when used with thinner oils and syntetics, a worn valve cover gasket can cause pretty alarming oil leaks. Fortunately, it's an easy fix that we can show you here!
Time Required: 30 Minutes
8mm Socket (5/16" Works too)
Emery Cloth or fine grit sandpaper (optional)
Pop the hood. My Cam gear cover and header heat shield are missing, but you get the idea.
Unhook the spark plug wires, move the throttle (and cruise, if equipped) cable out of the way, and unhook the breather tube from the back corner of the valve cover
With a socket, extension, and ratchet, remove the 10 bolts holding the valve cover on. Below is a diagram of the bolt locations:
Lift the valve cover up. It's likely that it will be stuck to the head pretty well. Don't break anything, but pull up firmly if you're sure all the bolts have been removed.
Clean the head-to-valve-cover mating surfaces with a clean rag, being careful not to let anything fall down into the head. Very carefully, use emery cloth or fine-grit sandpaper to remove stubborn residue on the mating surface. My engine didn't require anything more than a rag and some hard rubbing.
Remove the old gasket from the valve cover. It may crack or tear. Be sure to get ALL the gasket material out of the grooves.
Properly orient the new valve cover gasket (it can only be installed one way and fit properly), and press it firmly into the grooves. Take great care near the corners and where it routes around the bolt holes. Then rub a light coat of oil onto the mating surface of the gasket. I just dipped my finger in some of the used motor oil sitting exposed on top of my cylinder head for this.
Replace the valve cover onto the cylinder head, making sure the holes line up.
Starting at the four outer corners, replace the valve cover bolts and get them started on the threads only. Don't tighten yet. Then replace all the bolts.
Use the ratchet to tighten the bolts snugly but not really cranked down too much.
Replace the valve cover breather tube, spark plug wires, and throttle cables to their original position. Clean up any oil messes near the valve cover gasket, this makes leaks easier to spot.
Start the engine and let it run for a few mintes while you examine the area around the gasket for leaks.