Exhaust Fumes in Cockpit - and Driver's Head!

My brain hurts and I can’t find the solution to this exhaust issue. On track with windows closed and full vent blower…or with windows down plus blower, there is a significant exhaust odour. The rear clip is vented sides and rear, I’ve improved the roof scoop passageway, added another naca duct to the undertray and no improvement.The complete exhaust system was also changed incidentally, still with a central rear outlet… no effect. Been almost a year and I can’t solve it.

Anyone else have this issue? Oxygen bottle would be too heavy!

Welcome! Sorry it’s not a happier post.

Uldis may be the best to comment here. There’s a load of holes behind the seats that definately let air through (helps make the S1s, which I assume you’re talking about, A/c rubbish) that’s he’s mapped and plugged.


The firewall insulation looks intact, but I’ll go over it again. This may be grasping, but was there some mention previously of stuffing in the frame tubes to close them off?

Have you filled/covered the holes between the seats etc where the handbrake etc goes through the firewall?

Try a search on ‘sponge’ for other blocking efforts.


I thought I could point you out to the threads wert this has been discussed, but can’t find them.
Found only one of the first ones here but the pictures it points to are not there anymore.

Anyway yes, you have a problem and yes, it can be solved.

Air is getting into the cabin through LOTS of different places because the cabin is a low pressure zone (especially when you open the windows):

-holes in the rear firewall. You’ll have to remove the rear panel to see them
-the holes for the handbrake cable and brake pipe splitter
-big holes to the sills behind the seat belt tensioner
-bad sealing of the rear window
-holes in the front firewall (unused electrical or pipe holes I assume)
-and a big connection between the space behind the dash to the side sills.

For all but the last one you just need to go and cover them with either aluminum tape or whatever strong material you wish.
The last one I plugged with two big sponges tucked in there, you’ll have to dissassemble the dash first to get there.

But most importantly, all these holes would suck in only hot air from the engine bay.
The fact that they are fumes tells you there is an exhaust leak somewhere. Find that first. Suggest the use of a piece of garden hose as a stethoscope: one end to your ear and with the other following the entire exhaust system from the cyl. head to the very end listen for leaks.
If there is even a small one, you’ll find it this way.

Thanks for the good detail Uldis. I’ll get busy with the tape then. My previous exhaust was well sealed, but the new system has a slip joint at the collector and provides some new aroma. The cabin ingress is the concern for sure.

Many others must see this same heat/fumes issue. In general then, the S1 Exige aero being a kaam tail, rear spoiler, wing, and sloped engine cover must be very low pressure once at speed right where the exhaust exists!

The vents are open in the rear clip such that with roof scoop, side scoops and naca ducts in the lower tray you would hope the engine bay air would be ventilated out the rear exists …but is that how it works in fact?

I’m ready to try fans to push the air through …even if it only works on pit road, and … styling aside… direct the exhaust outlet to the ground and side. Any thoughts?

You’ll be Ok just by sealing the exhaust and all the entry points.
Just a small blowby on a sliding joint can produce nightmares, and you’ll seldom find it other than with the garden hose and your ear.

Regarding the fans, the best use is actually inside the cabin: close the windows and turn on the fan, you’ll prevent air ingress that way.


welcome to exiges.com

I agree with those above who say you need to find the leaky exhaust before you worry too much about the holes into the cabin.

If you can smell fumes you defo have a leak somewhere on the exhaust pipe.

That stuff can make you ill, I know (day in bed with fever like symptoms, and I count myself lucky…come to think of it my car has it in for me!). Definately don’t drive it for to long until you fix it.