Joe '87 S4

I was driving behind a truck pulling a trailer up a hill going about 40 mph. I went to pass him and floored it engaging the kickdown switch. After the car downshifted twice and quickly pulled away, I let off the gas and got back to a nice crusing speed. Right after that, I got a really strong exhaust type smell in the cabin which cleared up within about 30 seconds. The car drove normally the rest of the way and didn't show any signs of a problem anywhere. I don't usually floor it, but thinking back to last year, my sister drove the car for the first time and the same thing/smell happened when she had a little too much fun driving her first 928. Any thoughts on what the cause could be?

IcemanG17

Joe
I'm guessing the sunroof-windows were closed? Also was the vent or AC on? I wonder were the exhaust leak could be that it only happens under hard running/acceleration? Might want to check under the car to make sure the O2 sensor, cat-header gaskets and the rest of the exhaust is intact and tight?

Joe '87 S4

Sunroof and windows were closed, vent was open but no ac. I'll add it to the todo-check list for the next Devek appointment. I might take the car out and try it again tomorrow and see if it happens again. I think that's the first time this year I've used the kickdown.

SharkSkin

Could be blow-by... you may have a leak in your breather system. Engine compartment fumes get sucked right in to the HVAC blower.

perrys4

Joe, my car does the exact same thing.It is a 90 S4. I have not figured out what it is either. I am going to ask a lot of questions at Sharktoberfest. PLease post results if you find an answer. Thanks.

chaadster

That's unbelievable!

Joe '87 S4

Not really. I don't usually push the car speed-wise. I get more fun out of its corner handling ability.

Joe '87 S4

If you find out, please also post the answer.

WallyP

Check the hatch and make sure that the latch is adjusted so tha the hatch actually seals on the rubber gasket.

Check the battery box and make sure that the lid seals tightly.

Check for any missing tail light fastener seals.

Check the cover under the carpet over the gas tank access port.

mulik51

A lot of times this happens when the car goes above 5000rpm. Have you never smelled it from the car which was floring it ahead of you? I don't know how it happens, but I think it is normal, becouse all the cars I drove and saw do the same thing under hard, high rpm acceleration.

Just my 2cents.

Klim

WallyP

Nothing that allows exhaust into the passenger compartment is normal...

perrys4

Wally, I dont have any issues with the areas you suggested. Somone once suggested a "T" line or something up front near one of the fenders. Anything like that ring a bell? My smell seem to come from the vents. I usually dont runthe A/C so I would say that when I smell it I just have the fresh air vent open.

Joe '87 S4

I think the "T" line in the fender is for the charcoal canister and that's for fuel vapors. The smell is definitely coming through the vents and not related to any of the areas Wally suggested. It's coming from the engine bay. The smell almost has a little burnt rubber smell mixed in.

perrys4

We be talkin bout the same thing Joe!!

Joe '87 S4

Good to know I'm not alone.
It could be what Sharkskin suggested. If you solve the problem let me know and I'll do the same if I find anything out.