I was changing spaork plugs on 93 corolla (7A-FE). I noticed in cylinder 2 and 3 there was oil on the plugs. There is also light amount of sludge/oil on top of the valve cover and a lot on the seam where the cover meets the cylinder head. Is it just the gasket for the rocker arm (valve) cover, or is it a deeper problem with the head gasket?? Has anyone ever changed these? Are parts widely available? What about RTV sealant?
Oil leaks or dripping oil can happen as seals shrink and deteriorate due to age and heat. The 7A-FE used a o-ring style gasket around the valve cover and around the sparkplug tubes. A head gasket failure will generally show up as coolant loss or mixing of coolant with the oil (mayonnaise like consistency and appearance).
RTV sealant should not be used in place of the seal or to "seal up" leak - some cases will call for a sealant to be used in some areas (like around the timing belt cover). Some blends of RTV can wash away in hot engin oil and clog oil passages - not a good thing.
The replacement o-ring is not hard to do - might be a good idea to clean up the area first to determine where the leak points are - may be something else causing the leak. Hardest thing is to find a torque wrench sensitive enough to torque them down to spec's - something like 50 or 60 in. lb. or similar - very low torque. I believe someone one on this forum has replaced his valve cover gasket - just do a search for it.
I changed the one on a 5S-FE engine - very similar to the 7A-FE - about $15 for the gasket and about an hour worth of my time. Also gave me a chance to look at the valvetrain to see if there was too much deposits and adjust the valves (shims).
Good Luck.
