Replacing Valve Cover Gasket & Spark Plug Seals: 1997 Toyota Corolla, 1.6L

I'm going to go through how to replace the valve cover gaskets on a 1997 Toyota Corolla, 1.6L engine. I actually just needed to replace the spark plug tube seals (grommets), but since I had to take the valve cover off, it's gasket had to be replaced as well (though I believe there are gaskets that can be reused in this application as long as they are not too worn).

First detach the vacuum lines and move the wire harness over, and pull out the spark plug wire boots.

The valve cover is hard to get off, because it's been glued on by years of heat and the gasket hardening and frying onto it and the engine. You should be careful taking it off, because the cover is made of aluminum and it's soft. You can easily damage the valve cover or the engine with too strong of tools if you're not careful.

I used a hammer and a 2x4 for leverage to pry off the valve cover, but that's probably not the best idea, since I did gauge small marks into the valve cover. My dad told me it's a better idea to use a razor or a knife to loosen the cover from the engine, instead of trying to pry it off.

Be careful so the little bolt seals from unscrewing the valve cover nuts don't fall into the car or into the engine while you're dismounting the valve cover!! I took my valve cover off and while flipping it over 2 or 3 of these fell into the engine! Luckily I could get them out, but you don't want them falling in there and messing up the engine. Be sure to remove them before you lift off the cover, because they don't come off with the nuts.

A flathead screwdriver can be used to pry out the old spark plug grommets. It can also be inserted from the top of the valve cover, to hammer out the grommets. Just be careful not to gauge the aluminum.

You should use brake cleaner to clean the valve cover gasket. Maybe carburetor cleaner works too, I'm not sure. You want to make sure to have the surfaces of the engine and the valve cover clean before you put the old gasket on. The old RTV silicone sealant needs to be peeled away, maybe using a flathead screwdriver or knife, but carefully! A rag sprayed with brake cleaner works well to wipe off the engine surface where the gasket makes contact. You don't want to spray brake cleaner directly into the engine. However you can spray brake cleaner onto the valve cover, just make sur to wipe off and pour out the extra before reassembling the engine.

You can cover the engine with a towel during cleaning of the valve cover, so nothing falls in there!

The new gasket should be put onto the valve cover when it is clean and dry. The grommets can be inserted into the insets on the valve cover, after the old grommets have been pried out.

The new grommets can be easily pushed into the holes if they are wet with a little soapy water solution. This will evaporate and won't damage the engine, just don't use too much! Just a very little bit, and you don't need much soap. The grommets can be hammered in place with a rubber mallet or a hammer and towel. Be careful so you don't hit one side too hard, and make it go in crooked. They're hard to get out!! I tried to get one out after I did this, and I ripped it with a flathead screwdriver, and had to buy a new $40 set!

After inserting the gasket, apply a 1/16" bead of RTV silicone gasket maker sealant to the gasket. Also, on the engine, when it is clean and dry, apply a dab of RTV to the connection points where there are corners, or to grooves where oil could leak out, or to anywhere any serious scratches or damage has been done during removal.

The instructions for when to assemble the parts, after applying the sealant, are on the tube. Mine said to wait 10 minutes before assembling.

The new bolt seals should be tightened down, but not too tight. You can feel when the rubber is being squeezed down properly. Make sure to get the two extra bolts by the timing belt on there too!

Then just install the vacuum hoses, the wire harness, and the spark plug wires.

And now you're all done! Enjoy your less-leaky engine! :)