Issues

I have a 1986 Toyota 4runner SR5. I have just found out tonight after a little trip that i have a (what i think) a bad oil leak. It's comming from the right top front corner of the head area. Is this a head gasket or is it from the timing cover, or both? The leak is coming right below at #1 intake port where the head & timing cover meet. Its just real hard to tell at this moment. Is there a chance of it being the head gasket? Or more likely the timing cover? My rig has 212,000 on her. Also got a slight miss in her too. Just performed tune up on it, but its still there. Was thinking of checking for timing chain wear (which im sure she's never had it done) & also checking valve adjustment also. Any idea's or help on this would be very helpfull.

ozziesironmanoffroad

most likely the cover. hows your compression? and just so you know... an oil leak is NOT a symptom of a head gasket... thats oil in the coolant, coolant in the oil, a LOT of steam comin out of the exhaust, coolant loss, etc. im not much of an engine builder, and not sure if im correct on this one, but if you do the timing chain, might as well do a head gasket as well, since you're already mostly there. hope that helps

Matt16

Sounds like your valve cover gasket. Pull of your valve cover, check the condition of the black rubber gasket that rings around the bottom of the valve cover. It is about a 30 minute job to pull off the old valve cover and replace it. If you do so, use RTV sealant on the corners of the black rubber semi-circles at both ends of the head. Its really easy to do.

Once that is done, use some engine cleaner and a hose to clean off the old oil and see if that fixed it.

ovrrdrive

Sounds to me like someone tried to do a timing chain job on it without pulling the head and pan. It's almost impossible to put the timing cover back on without crushing the front of the head gasket. Once crushed, sometimes you can seal it back up with RTV as a temporary fix but eventually it will probably start leaking again.

Try pressure cleaning the front of the motor and cleaning the leaking area with brake cleaner, then sealing it from the outside with some black Permatex. You have about a 75% chance of stopping the leak for a while.

It could also be leaking under the half moons near the valve cover too. In this case just pull the cover and clean it really well and install a new kit and be sure to use permatex where indicated in the FSM. I usually run a bead under the half moon as well as on the top edges.