gholian

I replaced the rear main oil seal in my car last Christmas as it was leaking bad. I have an 82 Firebird V6 and it is a two part rubber seal that is used (I think they switch to a full seal on later models). The new seal started to leak after two weeks. I decided to replace the seal again a month ago. I tried a different manufacturer in the hope that this would help sort the problem. But it was not to be!. While the engine is running there is no leak but after it is switched off the drops soon appear. This is seriously doing my head in!!. What is wrong with it, The seals are in correctly (leap facing engine) and I used RTV sealant between the two halves of the seals. I checked the PCV system in case there was a fault that would put pressure on the engine and cause a leak. But no, PCV working fine. I have been looking at the archives on oil leaks and an oil sender unit is mentioned several times . Anyone know where this is on a 2.8L V6?. But if this was causing problem surely it would leak all the time and not just when the car is stopped. Also can oil leak from around the distributor, even though I checked and it looks fine.

If anyone can help I would truly appreciate it

Cruzin Kaz

There is a possibility that it may be your Intake, or even a Valve cover gasket. And yes most Distributors do have a gasket too, so that is a possibility also. You are 100% positive that each time your replaced the rear main seal, that it infact was leaking each time??

gholian

I am pretty sure that it is the rear seal. I have checked around with a torch and cannot see any leak from the top of the engine. I removed the dust cover and can see the oil drops on the center of the pan section where it meets the rear main seal cover.

Cruzin Kaz

Well... like I mentioned, it may be the intake, or even the distributor gasket. I would take a look up around the back, top area of the engine for any signs of leaking too.

gholian

I looked into changing the distributor gasket before but could'nt find any information on doing it. The distributor is in a really akward spot on the 2.8's. If I remove the distributor from the engine do I need to set the timing when I reinstall it.

Cruzin Kaz

Oh yes when removing the distributor you must mark it well to reinstall it. Both marking the base and the intake as to where it is now, and where the rotor is postitioned as well. If you don't do these steps properly, you will be having to set #1 cylinder back to TDC and reset everything. So you must be carefull and patient, but I will still look for any signs of leaking there before you go pulling it out. I would check the valve cover gaskets for leaks first, as they are not quite as much of a pain to do. If you degrease the engine well, it may help pin point the area causing the problems also. Get the engine nice a clean, and then drive it for a little bit till it shows signs of where the leak is coming from. But all in all in may be the Rear main seal again though, as the Crank may have some wear on it where the seal rides, causing it to leak even with a new seal sometims. It is a tough call, and will require some further investigation to really determine where the leak is really coming from.

gholian

There is a rubber C shaped saddle seal used between the oil pan and the rear main bearing cap (the seal is on the cap and the pan mates to it). I didn't put any gasket seal on the pan side of the rubber seal because there was none on the old one I replaced and frankly I didn't see the need for it. I tightened the big bolts on the pan to the torque settings given in the haynes manual (25 pounds/foot or something like that). I found I had to tighten these bolts all the way as there were drops of oil forming on the bolts. The cork pan gasket is pretty thick and in order to get the pan to mate tightly with the bear cap seal I had to tighten the crap out of the big pan bolts. Should I have put gasket seal on both sides of the seal?. Is it any harm having the bolts so tight?

gmsmallblockguy

You may be on to something with that. Your oil pan may be a bit bent not making even pressure on the seal, also you may well have the wrong pan gasket. I have over time come to just accept a leaky rear main on 2 piece seals as long as I am not loosing over a quart a month I usually let it drip and try to park facing down hill.

gholian

The pan seal is the correct one. It fits the pan perfectly. The only thing I can think to do is drop the pan a little without lifting the ehgine and squeze some gasket sealer on the saddle seal and hope for the best.

gmsmallblockguy

Normally I only use sealer where the 2 gaskets meet. Since the bolts were dripping at the proper torque your leak might be the pan gasket. Without removing the pan how did you clean the sealing surface?

gholian

I didn't do anything with it yet. I don't know how I will clean the two surfaces. I am going to have to think of something and get someone with small fingers.