Climate Control

Odor of Burnt Oil Entering through Vents

The elusive smell (stink) in my 88 S4 turned out to be the infamous "Y" plastic pipe connector for the charcoal filter unit in the right front wheel well. It sometimes would smell like fuel, sometimes like burning fuel mixed with exhaust, sometimes like burning oil/trans/coolant (take your pick). I've seen half a dozen of these cracked or broken completely. Huge improvement for a few bucks and I don't have to listen to anyone griping about the smell.

Marc White
81 and 88 S4


Here's Dr. Bob's "Y" connector experience:
I picked up a replacement plastic Y from my local dealer for a couple dollars, and put it in over the course of about an hour of fun and effort. Part of the process included replacing the hard plastic line from the cannister in the fenderwell to the Y. Seems the original mounting is limited with that hose, so a more flexible piece seemd in order. The hose I used is the same cloth braid covered vent hose that you all remember from the old VW days, between the oil filler and the oil-bath air cleaner. $4 at a local VW specialty house. With that more flexible hose, the connector is supported by tie-wraps to the filler hose for the washer bottle, hopefully eliminating the strain.

The reason the job took a whole hour is that I documented the procedure with the digital camera. I have a zip'd set of JPGs that shows the various steps and where the affected bits are located. Anybody that wants a set is welcome to it by e-mail. Just drop me a note. No write-up, but the pix are pretty self-explanatory.

Regards,
dr bob


I had a similar smell coming from the engine. When I did inspect the oil bypass hoses they were hard as plastic . When I pulled the intakes I found oil in the v of the engine from the leaks. I replaced them all and there are no more smells. Not cheap for oem hoses, though.

Kevin Berez (kaberez@mindspring.com)
'86.5 928S Auto Meteormetallic


I finally got around to replacing my heater valve (with new part from
David Roberts/928 Specialists) and the Hot Smell is GONE and no more
loss of coolant. The plastic valve body was leaking and there appeared
to be some leakage around one of the hose fittings.

A few weeks earlier I also replaced the plastic "Y" that connects to
the vapor cannister in the right front wheel well (a whopping $2.00
also from David R/928 Sp). The "Y" had deteriorated and cracked as
many others have witnessed. That did not cure the smell but I'm sure
it helped.

Also during the replacement of the heater valve I discovered and
repaired another vacuum leak. A small hose that connected to a vacuum
diaphragm at the end of the left fuel rail (?) just under the air box
was cracked. I repaired this but do not know what affect that had. All
I know is that all the vacuum lines are suspect and contribute to
overall functioning of lots of stuff. Everything seems to be working
fine now.

This list sure helps me know what to look for and expect even before I
have problems. And when I do, the answer has been tried and proven
several times. Thanks again to all.

Curtis Eames - 91 GT
Vancouver, WA