Oil dissappearing -

[Mr Two]

The car is a '90 325i, with an S52 swap done by Treehouse. It's mated to the stock 260 getrag

Originally I thought it was just the valve cover gasket, which was infact leaking, but I'm still losing oil even after it was replaced.

Just recently I noticed where it was going - after ragging on the car a bit, I noticed smoke coming from the top of the cats.

There is no smoke from the exhaust, at WOT or otherwise, so I'm not burning oil - it's leaking somewhere. The leak ONLY seems to happen during hard driving. I see no drop on oil pressure.

I'm pretty sure I need to replace the o-ring for the dipstick based on searching the boards here, but I see no leaks coming from it.

The rear output seal on the trans was replaced recently. A week after, I saw no fluid on the rear of the tranny. There's quite a bit back there now (The whole tunnel around the driveshaft up to one or two feet behind the tranny seems wet). When the car is parked, it does not drip down like it did before I replaced the seal, so I don't think the tranny is the problem. Somehow oil is leaking under hard driving (High rpm, low gear accelleration) and wind is blowing it back onto the cats. I hope, anyway. I don't want to have to mess with replacing some of the transmission seals again.

Any ideas to what is causing this?

[lifeiskaos]

valve cover gasket?

i have a similar problem on my m20. the valve cover gasket (rocker shaft seal) leaks oil over the tranny and drips onto my cat and smokes a little bit when i stop

[Mr Two]

I don't think it would be, it was replaced maybe three months ago.

Then again, it seems I have an S50 valve cover on the S52, and as such I'm using an S50 valve cover gasket. I wonder if that has anything to do with it?

[Brew]

Clean all the oil residue off thoroughly, drive the car for a couple days, and recheck.

Did you replace all the rubber grommets when you replaced the valve cover gasket?

[Hallen]

Have you checked your spark plugs for oil fouling? You'd be surprised at how much oil these cars can burn without smoking any at all. If the plugs are fouling, you might be looking at valve guide seals.

I don't know if the S50 is the same as the M20 and it has those rubber rocker arm shaft seals, but that's worth checking if they weren't done before.

And how much are you losing in how much time?

[Mr Two]

valve cover gasket?

i have a similar problem on my m20. the valve cover gasket (rocker shaft seal) leaks oil over the tranny and drips onto my cat and smokes a little bit when i stop

It was replaced very recently. I'm going to see if I can check for leaks there. I might be related to the whole wrong valve cover issue.

Clean all the oil residue off thoroughly, drive the car for a couple days, and recheck.

Did you replace all the rubber grommets when you replaced the valve cover gasket?

A friend who used to work at Treehouse was over at the time, and went to town on it while I was doing some paint related work. AFAIK He did.

Have you checked your spark plugs for oil fouling? You'd be surprised at how much oil these cars can burn without smoking any at all. If the plugs are fouling, you might be looking at valve guide seals.

I don't know if the S50 is the same as the M20 and it has those rubber rocker arm shaft seals, but that's worth checking if they weren't done before.

And how much are you losing in how much time?

Before replacing the gasket, they were gunked up with oil. The valve cover gasket was leaking around the plugs.

I can't really say as far as oil loss / time. I need to top her back off and measure it I guess. I hope I don't have to crack open the head, I want to spend that money elsewhere! :(