This weekend, on the Dragon I experienced a strange problem. Just as the title suggests it's a large smoke cloud. I assumed it was a torn CV boot slinging grease only at high axle angles. The kind you get when pushing hard thru corners. On further examination I couldn't find a tear in the boot.

What are the odds of a bad seal on the front diff leaking gear oil onto the cat, only in left-hand turns? Assuming I keep tabs on the gear oil in the diff, can I get away with this?

Any other things in that area that can leak onto the cat I need to look into?

Other than that, Kat absolutely performed flawlessly.

Could the smoke be coming from the exhaust? If so, it sounds like a bad PCV valve. Had the same problem on my '87 GL. Cheap and easy fix.

Could the smoke be coming from the exhaust? If so, it sounds like a bad PCV valve. Had the same problem on my '87 GL. Cheap and easy fix.

I honestly don't believe it's coming from the exhaust. I stopped to check it out , and the smoke definately seemed to be coming up off the cat/con. It also stunk to high heaven of gear oil, or grease. Also it's coming from the passenger side, and the exhaust is on the driver's side.

I had a problem with my old 90 Loyale. Hard turns (mine was to the right) allowed oil to be slung into the combustion chamber I think had something to do with the pcv setup. There was a Subaru fix for this (I never did it) maybe with a check valve?? It's been a while. I'll try a search.

It would do a 007 smoke!!

Found an old link http://www.ultimatesubaru.org/forum/showthread.php?t=27999&highlight=smoking+on+turns

It describes my problem but solution for you may be just to get a Subaru PCV valve. Has yours ever been changed? Again genuine Subaru recommended.

Thanks guys, but the smoke is definately coming from under the hood. What you guys are describing is from the exhaust pipe.

IMHO I feel it's coming from an axle seal, or a tiny tear in a CV boot. I'm just wondering which would be more common, and will either do damage if I keep an eye on them.

An axle seal would be replaced when I do brakes next. As a "while I'm in there" thing. A torn CV boot I'll let go until it starts making a noise. Especially since Subie CV's seem so bulletproof.