Exhaust/gas smell blowing through heat/ac vents when not set to recirculate
 

Hi,

I have a 98 Audi A4 1.8T and smell a mixture of exhaust/gas (mostly exhaust) blowing through the heat/AC vents when the car is at stopped and the climate control is not set to recirculate. The smell is strong under the hood near the exhaust/turbo as well.

I was reading a post on this forum where someone specifically asked another poster if this was the case when trying to troubleshoot an issue for them... What are possible causes of this?

I've had the vehicle in two shops which could not find exhaust leaks. I have an appointment with the dealer in a few weeks and am starting to wonder if a complete replacement of the turbo is going to be something required to fix this.

The car seems to run fine aside from this smell. There is no boost gauge and I haven't owned it long enough to know if the car used to respond differently.

Thanks for any help,

David

Make sure your catalitic convertor is free and unclogged, they will cause exhaust backups and overwelm anyone when the smell coems back up the pipe, even if there are "no leaks"

Also you can get a gas/exhaust smell from your evaporator/purge canister, or "charcoal canister" as it's commonly referred to, which is designed to burn off gas fumes from the gas tank.