Rear main seal question.......

[BDAWK2002]

My car has been losing oil.....a lot of oil,like a quart a week.I'm wondering if it has anything to do with the fact that I changed the rear main seal two weeks ago.The only problem is that I cant find any sighn's of oil leak anywhere.No stains in the driveway,no smoke out of tail pipes & no oil splashed anywhere on the motor.I mean not even a drop...w.t.f. If the rear seal is leaking does it leak only when running?And if it does only leak when it runs wouldnt it splash around a little bit.I went under the car and found no sighns of leaks around the rear of the motor.Not a drop.....Any ideas.

 

[Zero Signal]

Maybe bad rings or a blown head gasket?

 

[HISSIN50]

RMS leak of any consideration would leave some spots, stains on components downstream, etc.

But it has to be going somewhere......

Good luck.

 

[mo_dingo]

You might want to drain your coolant and see if it's getting there. It will start to look like milk chocolate instead of bright green.

Also yank all 8 plugs and see if any aren't dirt brown. That should tell you if it's getting into the combustion chambers.

Another option would be to add a flourescent dye to the oil, and see if you can find it coming up in a strange spot, like valve covers, intake, timing cover, etc.
Scott

 

[WhiteDevil]

If you cant see any place that its leaking and the car is running well its probably valve seals. mine used to burn a quart every 3k miles then after i did my edelbrock heads(new valve seals) it has pretty much stopped.

 

[BDAWK2002]

If you cant see any place that its leaking and the car is running well its probably valve seals. mine used to burn a quart every 3k miles then after i did my edelbrock heads(new valve seals) it has pretty much stopped.

It's actually burning a quart every 1000 miles.The motor has a 104,000 miles on it so maybe it is the valve seals.I dont see any smoke though wouldnt I see smoke?The motor has been getting a little more of a workout now that I have a 5 spd and 3.73's.It run's beautiful though. I'm gonna check the plugs and coolant tomorrow.Maybe I'll be doin the H.C.I sooner than I thought.

 

[BDAWK2002]

You might want to drain your coolant and see if it's getting there. It will start to look like milk chocolate instead of bright green.

Also yank all 8 plugs and see if any aren't dirt brown. That should tell you if it's getting into the combustion chambers.

Another option would be to add a flourescent dye to the oil, and see if you can find it coming up in a strange spot, like valve covers, intake, timing cover, etc.
Scott

I dont see any coolant in the oil.Would it be mixed??I havent checked the coolant but I will.I think the coolant in the overflow was brown though.

 

[Rootus]

A friend of mine was going through several quarts of oil every 1000 miles (fast enough that if he topped it off, in 600 miles he'd get the low oil light!)... and it really didn't make that much smoke, just a good puff when he romped on it. Nothing on the ground or on the underside of the car, all of it going out the pipes. Turns out he had a cracked oil control ring. And that was it. This was on a '95 GT vert with about 80k miles. If I didn't see it with my own eyes, I'd never have believe it...

Dave

 

[BDAWK2002]

A friend of mine was going through several quarts of oil every 1000 miles (fast enough that if he topped it off, in 600 miles he'd get the low oil light!)... and it really didn't make that much smoke, just a good puff when he romped on it. Nothing on the ground or on the underside of the car, all of it going out the pipes. Turns out he had a cracked oil control ring. And that was it. This was on a '95 GT vert with about 80k miles. If I didn't see it with my own eyes, I'd never have believe it...

Dave

I hope I dont sound to stupid but what is a oil control ring?

 

[Rootus]

I hope I dont sound to stupid but what is a oil control ring?

It's a ring around the piston that allows the wrist pin, rings, and piston walls to be lubricated with oil, but keeps that oil from entering the combustion chamber. There is also a compression ring (heck, maybe there's two, I've never rebuilt a 302) that seals the combustion chamber to maintain pressure.

With a cracked oil ring, the oil can seep into the combustion chamber. Surprising how much you can lose that way. The only way to find out for sure is to tear down the engine. I'd recommend proving it's not something else first .

Dave