I am assuming that this is just an exhaust leak somewhere near the manifold/cat, but I am curious if there could be anything else causing this.

About 2 weeks ago I noticed as i was driving with the a/c on a oil/exhaust smell coming through my vents. It is coming in strong enough that i get light headed when the vents are on. I checked it out a little while afterwards and couldn't really find anything. I don't have a warranty anymore and when I called the dealer they said they would charge me over $170 just to pretty much open the hood. They said they would also charge their hourly rate which is insane. I brought the car to Meineke (since they examine for free) and they couldn't find anything. They said that they were pretty sure there was a leak but they couldn't find it anywhere. They said that they couldn't find the black spots that would indicate where a leak is. Any ideas what I should do?? I am thinking that I need to just replace the entire system with a milltek header/cat and exhaust. Any ideas???

Certainly sounds like a leak somewhere to me. Surely with the direction of air flow it must be between then join of the manifold to the head, flex joint or the cat back join?

Personally I would get it sorted! Benzene and others are really not good for your health ;)

If it's coming in through the vents it's pretty likely to be in the manifold region (where the exhaust joins onto the engine block).

It might be a good excuse to go aftermarket - but worth getting it checked again as it may just be a perished seal.

They said that it could be the gasket but they can't figure it out. They quoted me at 5 Hours worth of work just to replace the gasket. That is close to $500. I think that aftermarket must be the way to go. I was thinkin of doing the milltek header/cat. I planned on doing it in the future anyway, I guess I'll just be forced to do it quickly!!! I hope that will solve it! Thanks for your replies!!! Is there anything else it could be? Someone was suggesting something happening to one of the cylinders to cause an oily exhaust type smell. That scares me!!

that's not fair! Only Meineke looked at it for free. Everyone else has no customer service skills In the north east US. It's aweful! I have been wanting to do some mods for awhile, I just haven't had the money to do it. I just hope that the exhaust is really the problem! I really hope that it isn't something internal or something. It's driving me crazy!!

If you are smelling fumes inside the cabin then you need to check the rubber gaskets between the engine bay and the firewall. Make sure that they are all in place. The cowl vents at the base of the windscreen supply high pressure air to the ventilation system, as well as the air intake.

For the fumes to be getting into the cowl area does not sound right. The ventilation system does not draw air from the engine compartment. Do you run the ac in the recirculate mode or drawing in fresh air?

An oil smell could be coming from something as simple as a leaking valve cover gasket dripping onto a heated exhaust manifold. Otherwise the most common place to get oily smells would be at the tailpipe from unburned blowby around a bad set of rings or oil getting sucked past bad valve guides. It is my thinking that any exhaust leak would be accompanied by an increase in noise. Can you hear anything unusual?

Have you installed any other mods to the car?

The dealer takes the cake with an upfront $170 charge. Was it Hartford or Fairfield?

Good luck.

P.S. Had another thought. Is your car equipt with a sunroof? Do you smell it more with the sunroof popped up?

Nice explanation! You from CT?? I need someone to talk to about my car that has experience with them. It was Stamford Mini. My car doesn't sound the same as it has in the past. I seem to get a more airy sound under the bonnet. The supercharger is a bit louder than it used to be. The car doesn't seem to have as much power (sometimes more than other times). I havent noticed the smell more with the sunroof open. How can I check those rubber gaskets myself? The smell doesn't come through the vents if I have circulate on, only when it is pulling air from outside, and more so at highway speeds. It's not really noticeable at slow city speeds, just the power loss is noticeable. I'm so confused! haha

Mini morgan and mini cabrio are right in my book. Power loss and a smell of fumes definitely sounds like a leak somewhere in the exhaust system or even a crack in the system somewhere.

Whichever - it needs checked out as breathing those fumes doesn't do you any good health wise and it must be pretty bad and serious if it is making your head hurt/dizziness - I'd get it looked at asap for the sake of your health!

If you want to check out rubber seals in the firewall/bulkhead - grab a torch and examine the bulkhead at the rear of the engine compartment - you should be able to see most of the rubber sealing washers - might need to be up on ramps and engine undertray removed (4/5 bolts) to get a proper look. But the loss of power and 'airy sound' or slight blowing would indicate to me that there is a misalignment or serious leak in the system - you are losing power as the burnt gases aren't getting the chance to escape properly changing the flow and dynamics of the exhaust system and the efiiciency of it's extraction - potentially leading to lesser combustion as the car will be getting less oxygen/air on the combustion stroke as there are still some unburnt gasses lingering in the head/cylinders from the incomplete extraction of fumes at the exhaust stroke.

It might be worth looking under the bonnet/hood whilst a friend revs the engine and look for the tell tale exhaust smoke to establish where the leak may be. - Make sure it is a good friend you can trust not to slip it into gear, run you over and steal your MINI though.......

One last thing that might be worth checking is the position of the exhaust exit/tail pipe - if the hanger (or whole exhaust) is out of alignment the exhaust position can sometimes get a backflow under the car of exhaust gases due to the aerodynamics - clever things exhausts - but a pain when trying to track down leaks. This can sometimes also occur when an aftermarket spoiler is fitted at the rear of a car - the exhaust needs a good clear exit to push out all it's gases and prevent the gas being trapped under the car and finding it's way back into the cabin through the floor/boot/trunk area.

Happy hunting!

Also.... fill a spray bottle with a mixture of water and soapy car shampoo, and spray away. Any air leak should be visible with bubbles.

This is useful for minor leaks, sounds like your one should be more obvious though ;)

I actually have a similar problem at the moment but hopefully sorted when I next get under the car. When I stop the fan draws in exhaust fumes but when driving along its fine. If the bonnet is up I cant smell anything so must either be back flow where the exhaust is hanging low maybe or where my decat meets the manifold. Will sort it when I get time.....at the moment I just use recirculate or dont use the fan.

I have a similar problem as well. It only happens on start up though and then it goes. I think it is coming from the joint in the middle of the JCW cat back system as I cannot seem to seal the joint 100%. The compound I use on it sets but when the water which comes out the exhaust flows it finds a path through this joint and exhaust gases also start to come out. I can feel it blowing if I lie under the car and put my hand around the joint.

What are people using on their joints?


Regards


James