Gas vapors in cabin while on boost

jay71 · 11-09-2008, 11:49 PM

I've been noticing a strong smell of gas fumes in the cabin while on boost. This is my first fall/winter in the car where I've used the heat- until now the windows/sunroof have been open for the majority of my driving. I have relatively new GHL headers w/heat (approx 4000 miles on new headers) and I'm starting to wonder if I have a crack or something that is allowing gas fumes from the exhaust to leak into the heater boxes & cabin. My AFR drops to 10.5-11 at 0.9-1bar- and the gas smell occurs. Otherwise I don't smell/notice anything during non-boost driving (AFR is typically in the 13-14.5 range while cruising). I have a Leask adjustable WUR- and I know I need to tune it a bit to get it a little leaner while on boost...but regardless of the air/fuel mixture I would think the only indication of low AFR should be suboptimal performance/low readings on my gauge; not gas vapors in the cabin. Am I correct in thnking I have a header issue- or is there something else that may be causing the fumes in the cabin at low AFR's? Thanks, in advance, for your help.

gogomobil · 11-10-2008, 01:37 AM

same problem here without adjustable WUR, on boost AFRs hit low 10s in midrange and climb up to high 11s close to redline. I run GSF headers and can also smell the exhaust/gas fumes while accelerating. I am also afraid I have a leak somewhere. Maybe I should unhook the heaterhoses that are connected to the headers and see what happens? How can you tell if there is a leak inside the heaterbox from the header?

Miguel Antonett · 11-10-2008, 03:36 AM

It sounds like a leaky headers. A CO tester would help identifying the gas. Try a "home" smoke/CO detector...

jay71 · 11-10-2008, 08:17 AM

Quote:

Originally Posted by Miguel Antonett

It sounds like a leaky headers. A CO tester would help identifying the gas. Try a "home" smoke/CO detector...

Thanks Miguel- good idea with the CO monitor. Up 'til now I've been using the, "am I dizzy?" test- CO monitor is probably more accurate.

beepbeep · 11-10-2008, 09:09 AM

Quote:

Originally Posted by jay71

... I have relatively new GHL headers w/heat (approx 4000 miles on new headers) and I'm starting to wonder if I have a crack or something that is allowing gas fumes from the exhaust to leak into the heater boxes & cabin.

Check your headers for cracks. Usually between heat boxes and pipes. CO is odorless. Unburned fuel (due to AFR of 10:1) is fortunately easier to detect with your nose. You might have exhaust leak but be able not smell it until it's pig-rich.

Miguel Antonett · 11-10-2008, 10:11 AM

Hey Beepbeep, is that an actual hole created by the rubbing with the heater box seam?

If so, what headers are those? Not to even consider. That could be considered willfull...

gogomobil · 11-10-2008, 10:34 AM

look at that hole.
Surely enough to get gassed inside the cabin while driving.
I didnt know that CO is odorless, will try to put a CO tester in front of the cabin air ducts and see what happens. maybe it is just the gasolinevapors of the fueldump causing this smell. Goran, did you have the typical tap tap tapping noise from that hole or did it still sound normal?

beepbeep · 11-10-2008, 11:11 AM

It's not my car, it's from one gentleman here in Sweden who was also registered here on Pelican. I just borrowed his pictures in order to prove the point. He can tell which manufacturer it was if he wants to.

Anyway, if aftermarket headers have custom made heat chambers spot-welded to tubing (to keep them in place), those weld-spots are often rotten away by high heat. There is a good reason for OEM chambers are made the way they are.

rsrmike · 11-10-2008, 12:40 PM

All the more reason to use either factory of SSI...

jay71 · 11-10-2008, 08:50 PM

Thanks for all the replies, folks. I especially appreciated Goran's pics- those headers look familiar! I have less than a year a a few thousand miles on mine. I'll test GHL's "lifetime warranty" this week. Hoping they'll just send me some new headers in exchange for mine instead of making me send mine in for repair, rendering my car useless for the duration of the repair/shipping turnaround. Thanks again.

A930Rocket · 11-11-2008, 04:59 PM

I think you'll be happy with GHL. They worked with me on a problem I had and Brian ( the owner ) is the best.