Hello everyone. I tried searching for this topic but nothing came up. So I'm wondering if anyone can give some help.

I just bought my 2006 MCS on Memorial day. So far no issues yet. Love My MINI. It came with the Borla Sport Exhaust - Aggressive on her.

One thing that I'm perplexed about is Exhaust Fumes coming in the cockpit ONLY under hard acceleration (i.e.: 5000-6000 rpm going thru gears on the On-Ramp to the Interstate).

Under normal to even medium driving everything is fine no fumes. Of course this is when I have the A/C system is set to AUTO and windows/sunroof closed.

My first thought is maybe when they put the exhaust on they didn't use the Wurth (sp?) pipe sealer when fitting the Borla pipes together or to the CAT?

Or do you think I may have an exhaust leak?

I have no CEL on.

Thanks to all that may have some clues!!

 

During a hard acceleration, obviously things get pretty hot specially around the exhaust. What happens is that as things get hot, things that normally won't burn will get burnt. I wouldn't know what is burning under your hood but the potential candidates are loose wirings or anything that is close to the exhaust pipe plumbings. Dirt and grease accumulation also maybe burning.

As these things burn, they make it through the vent and you smell it.

Leaking exhaust, you will hear it specially as you accelerate and it is obnoxious to say the least. If the leak is minimal, you may not notice it as much specially with your exhaust system. If this is the case, not much you can do; either you start looking for the leak visually or let it be until the leak gets larger and you will be able to visualize the leak rather easily.

Next time, keep the AC on recirculate mode and see if the smell decreases.

In terms of CEL, unless the leak is substantial before the cat that O2 sensor picks up abnormal amount of O2 in the system post cat, it won't throw the code.

With that kind of leak to a point where there is a code, you should be able to hear the leak and should been annoyed by it by now.

HTH

 

I would start off by checking to see if the gasket between the exhaust and cat is good. This connection is just right under where your shifter is. It's possible that it is leaking then going up this way.