Oil leaking from head gasket

[Mark]

I've had a dripping oil problem for a couple of years. At first it was just a drop or two a night and I assumed it was from the drain plug. Now it's several drops and the bottom of the transmission seems to be wet with fresh engine oil at the end of the day after driving it. I had a good look around the usual spots (valve cover gasket, distributor shaft, camshaft seal) and all seem to be dry. I replaced the distributor o-ring since there seems to be the worst leak right under it. That didn't change anything. The area behind the timing belt cover is dry. The rear crankshaft seal area was also dry when I recently removed/replaced the transmission. The two areas where it seems to be coming from is the head gasket near the alternator and the head gasket near the starter. I have no indication that the head gasket is leaking internally. Has anyone had this external oil leak from their Tercel head gasket before? Are there any suggestions other than "replace the head gasket"?. A few internet searches suggested cleaning and smearing the gap between the block and head with high-temp sealant, but I can't see that lasting for long.

[larry mcgrath]

the main spot for an oil leak from around the altinator is the oil pressure sending unit-located on the engine block behind the alternator-these are noted for leaking . the sender is threaded into the main oil galley,with one wire attached . a 10.00$ part .good luck Larry.

[dlb]

i would clean the engine really thoroughly, and then drive for an hour or day or whatever it takes until you can see the leak coming out. that will give a clearer idea of exactly where it's coming from. i have not encountered oil leaking from a head gasket but there's lots i haven't seen.

[TURTCEL]

I actually have a very similar concern on my Terc. The mating area between the head and the block all down the driver's side seems to get a little oil seepage once and awhile. I clean it really good with brake cleaner so the surface is fresh to start and then I drive it too look for seepage. DLB makes a good point to start with a "clean slate" so you can narrow it down.

I don't really use oil so I am not too concerned until it becomes a major issue.

For $6 at NAPA you can buy oil leak testing dye. Clean engine, pour dye into oil, run for a while, use a black light to locate leaks (buy a bulb from a party store)...it will glow green where it leaks. The dye does not compromise your oil quality so no need to change it after the dye test. I have found many leaks with this test...on my old VW (thank the world I sold it).

Just a thought if you are having a really hard time narrowing down the leak.

Peace

[Mark]

I'll probably get some carb or brake cleaner and clean up the area with an old toothbrush and some shop towels tomorrow. There might be enough oil flow at idle to let me see the leaks in my driveway.

[TURTCEL]

I would lay a piece of clean cardboard down under the car when you park it to help narrow down where the leaks are coming from. Just remember that oil can run down frame rails, hoses, etc....and drip in different locations than where the leak is coming from. You could remove the splash guard so that the drips are more free to fall straight down from leak point too.

Good luck.

Peace

[Mark]

The problem is, any leaks above the sump would occur only when the engine is running. When it is shut down overnight, the oil drains back to the sump and doesn't leak. I've put down some plates (everything else blows away) under the engine/transmission and the drips are from under the transmission. That's because when I'm driving, the oil leaking from the engine blows back onto the transmission and then drips down from there. I tried spraying some brake cleaner around the head gasket area, but the engine was still too warm and it instantly boiled off. I'll try it again someday when the engine has sat for long enough to cool down.

[Petros]

Not likely it is leaking from the head gasket, more likely it is coming from above there (probably the valve cover gasket) and than following the joint around the engine and dripping down to the block from the head gasket joint.

the only place where pressurized oil passes through the head gasket is on the front left corner next to the head bolt. the gasket has an extra seal round this location, if the head gasket is damaged enough to allow this to leak, the car would not run since the combustion chamber pressures are about 10 ro 20 times higher than the oil pressure. It seems extremely unlikely it is the head gasket.

The oil sender at larry suggested is the most liekly culprit if your seals and valve cover gasket are all good.

[Mark]

The area around my oil sender is dry (but dirty). The wettest area is the corner around the starter. I'm starting to lean towards that rubber piece that comes down from the valve cover at the rear of the engine. I've had a look with a mirror and didn't see what looked like oil running down, but today I felt with my finger and it felt wet. It's just not that visible in that awkward spot. I wiped up the area under it and stuffed a wad of shop towels against the rear of the engine to absorb any oil that leaks from this valve cover seal area. Tomorrow after I drive it to work and back I'll see if the area below it is oily again. Hopefully the towels won't catch fire.

[larry mcgrath]

The o-ring that seals the distribetor which is above the starter could be leaking also-this is a common spot for oil leaks if the valve cover gasket is dry. Larry

[Mark]

The o-ring that seals the distribetor which is above the starter could be leaking also-this is a common spot for oil leaks if the valve cover gasket is dry. Larry

Replacing that 0-ring was one of the 1st things I did (hence my timing light issues in another thread). It turns out that the area around it is dry so the leak under it must be from somewhere else. I'm still leaning towards that rubber "U" at the back of the valve cover.

[Mark]

So after driving around for the day with paper towels jammed against the "u" thing at the back of the engine, the towels were soaked with oil and the area below it was reasonably dry so I guess that's what it was. Hopefully it's as simple as carefully removing it (it's probably brittle by now) and sealing it with gasket-maker. I doubt they are still available new.

[dlb]

are you talking about the semicircle rubber part? you can definitely still get them. that's a nice, easy fix.

[marlinh]

If that seal is brittle, it is probably worth replacing the whole gasket. It isn't that expensive.

[Mark]

are you talking about the semicircle rubber part? you can definitely still get them. that's a nice, easy fix.

Where would you get them (dealer?) and what the heck are they even called?