Before you begin to change leaking valve cover gaskets, let the car sit overnight to let any oil under the valve covers to seep back down to the pan. If the oil return holes in the head are partially clogged, it will take a while to fully drain. Once you have the valve covers removed, you can address the partially blocked drain holes by using a piece of coat hanger wire to "ream" the holes for better drainage. Blocked holes many times are the reason that the valve cover gaskets will leak.
Once you have the valve covers removed, clean them throughly in parts cleaning solvent. Repainting the valve covers is a good idea while they are off. Keep in mind that all traces of oil must be removed if the paint is going to adhere to the covers. Once that they are totally degreased, you might consider having them bead blasted to finish cleaning the surface, or you can use a commercial paint stripper, and then follow up with a coarse steel wool rubdown. Before you go any further, check the gasket seating surface on the valve cover to make sure that it is not deformed. If necessary, you can straighten it using a light weight hammer, and gently tapping on the edge while backing up the metal with a piece of wood, such as a 2" x 4" block. A final washing with dish-washing detergent is a good way to remove any oil traces, followed by a wiping with a commercial wax & oil solvent.
Now that the valve covers are throughly cleaned, it is time to paint them. I suggest that you use a spray bomb of self etching primer on the bare metal. Then within 24 hours, put on the top coat of a good engine enamel paint, and allow to throughly dry for a couple of days.
Next it is time to replace the valve cover gaskets, and I use a thin coating of weatherstrip adhesive to adhere the new gaskets to a clean cover.
Valve cover gaskets come in either rubber or cork, and everyone has their preference. I prefer the rubber gasket, since it can be re-torqued if necessary multiple times, unlike cork which has a tendency to crack if you tighten them too much. On the head side smear a light coat of wheel bearing grease or chassis grease on the head where the gasket is going to be in contact with the head.
It is time to install the fasteners, and you want to only get them started in the the threaded holes, until all fasteners are installed. Once you have them all started, using a nut driver of the proper size, slowly screw them fasteners down until they just touch the top of the valve cover, and move onto the next fasteners. Keep going around the valve cover until you have tightened all the bolts. By using a nut driver, you are not going to over tighten the screws, unless you use brute force. The idea is to get the valve cover tightened fully, but no so much so that you are distorting the metal edges of the valve cover. After you drive the car for a few hours, re-tighten the nuts using the same technique as described above. You might have to re-tighten the valve cover bolts a number of times until the gasket is fully seated and conforming to the head.
Once you have the valve covers removed, clean them throughly in parts cleaning solvent. Repainting the valve covers is a good idea while they are off. Keep in mind that all traces of oil must be removed if the paint is going to adhere to the covers. Once that they are totally degreased, you might consider having them bead blasted to finish cleaning the surface, or you can use a commercial paint stripper, and then follow up with a coarse steel wool rubdown. Before you go any further, check the gasket seating surface on the valve cover to make sure that it is not deformed. If necessary, you can straighten it using a light weight hammer, and gently tapping on the edge while backing up the metal with a piece of wood, such as a 2" x 4" block. A final washing with dish-washing detergent is a good way to remove any oil traces, followed by a wiping with a commercial wax & oil solvent.
Now that the valve covers are throughly cleaned, it is time to paint them. I suggest that you use a spray bomb of self etching primer on the bare metal. Then within 24 hours, put on the top coat of a good engine enamel paint, and allow to throughly dry for a couple of days.
Next it is time to replace the valve cover gaskets, and I use a thin coating of weatherstrip adhesive to adhere the new gaskets to a clean cover.
Valve cover gaskets come in either rubber or cork, and everyone has their preference. I prefer the rubber gasket, since it can be re-torqued if necessary multiple times, unlike cork which has a tendency to crack if you tighten them too much. On the head side smear a light coat of wheel bearing grease or chassis grease on the head where the gasket is going to be in contact with the head.
It is time to install the fasteners, and you want to only get them started in the the threaded holes, until all fasteners are installed. Once you have them all started, using a nut driver of the proper size, slowly screw them fasteners down until they just touch the top of the valve cover, and move onto the next fasteners. Keep going around the valve cover until you have tightened all the bolts. By using a nut driver, you are not going to over tighten the screws, unless you use brute force. The idea is to get the valve cover tightened fully, but no so much so that you are distorting the metal edges of the valve cover. After you drive the car for a few hours, re-tighten the nuts using the same technique as described above. You might have to re-tighten the valve cover bolts a number of times until the gasket is fully seated and conforming to the head.