Kerry Chadderton

I'm pretty well at the end of my rope with this. I believe that I've also read every thread and forum on this topic and followed all advice therein. I'm hoping one of you can help talk me through this. First a little background:

84 N/A 140,000 miles, primarily a DE car, drive it < 2,000 miles a year.
Replaced WP (updated), TB & BS belts, seals and all rollers 4 years ago.

After first DE, 2 years ago, I noticed a very small dripping oil leak right below the lower BS tensioner pulley. This accelerated with the next two DEs. I decided to replace all seals and belts again 2 months ago. This time I took everything off the front of the engine, including the cooler/OPRV assembly. I bought a comprehensive list of parts from pelican including the spacers, oil pump gear and the OPRV tool. I cleaned and inspected everything for damage. It was a careful install.

Same leak. The TB, Camshaft & oil pump areas are clean and dry. The oil is in a mist pattern that ends where the BS belt crosses over from bottom to top shaft and runs down the surface of the front and rear covers evenly. The front of the oil pump is dry. Crank pulleys are dry. The balance shaft gears do not show an oil slinging pattern from center to OD.

There is a visual mist when revving the engine, covers off. It is impossible to identify the source.

Monday I replaced the two balance shaft seals (30x47 & 30x48) using grey RTV on the OD (in desperation). I replaced the onion skins again checking to make sure they weren't doubled. I also used thread sealing compound on the bolt threads per the advice of a write-up I read on the problem.

Still...same leak. I had a DE on Friday. Same amount of leaking I had before all this work.

I'm using Mobil 1 15w-50. Oil pressure is 5 bar cold at idle, 3 bar warm at idle.

I don't know what else to do. Thoughts?

V2Rocket

Did you install the small o ring on the crank after the pump drive gear went on?

Kerry Chadderton

Most definitely! And, the oil pump face, the shaft snout and the TB/BS pulleys are clean and dry there.

william_b_noble

the balance shaft seal carrier has a black 0-ring on it that seals it to the block - on every car I've looked at, these have turned to very hard and brittle rubber rings - and then they leak - did you change them? did you check that the oil filter isn't leaking - maybe a pinhole or something in the filter or the filter seal?

Kerry Chadderton

Yep, both housing O-rings were replaced along with seals, spacers and onion skins...twice. I've gone through two oil changes, two filters. No leaks there. Oil pressure sender replaced too.

This leak is within the belt covers. It's driving me insane. I can change a 944 belt system in 59 minutes now. That's how many times I've gone back in there.

This is a misting oil leak. It doesn't have an obvious single source.

william_b_noble

from what you have said, if there is a "visual mist", it must be coming from somewhere - I would guess that it is coming out one of the oil seals and getting slung around by the rotating shaft - try removing the balance shaft belt, and rev it again, if you still have the mist, it is NOT the balance shafts, if it goes away, then that's where to look. it could be slung off the mainseal also, so if it remains with the balance shaft belt removed, I think I'd look at the back of the cam belt pulley to see if there is evidence of oil - maybe with a dental mirror.