Trouble with Fumes
Trouble with Fumes This may get moved but if it does, oh well. I have a 4" cowl hood and I was wondering if anyone else with a cowl hood has trouble like me with fumes coming back into the car with the heat or defrost on at a stop. When I am moving its not a problem, but when I come to a stop and have the defrost or the heat on, I get fumes in the car bad enough to burn your eyes, and the car is tuned properly. I have to turn off the heat/defrost everytime I come to a stop unless I want to choke. I also have removed the Air Conditioning but I dont think this has anything to do with it. My tuner seems to think its b/c of the cowl hood letting fumes into the vents at the base of the windshield. Anyone with this problem or heard of this problem, or have any idea what may fix, help, this?
Yup, sounds like your getting fumes from under the hood pulled into the engine compartment by the cowl area. The heater (and A/C) pulls its fresh air from the base of the windsheild at the cowl area so if it's not closed off with a flat hood it's possible to get that air pulled right in through the cowl and into the car. Do you still have your PCV system hooked up or just some breathers on the car? If you don't then that's probably the origin of your fumes.
I have half the PCV hooked up....don't ask its a conglomerated mess. On the driver's side valve cover I have a breather. My pcv system was off a 98 car. The valve covers I have are centerbolt style now since I have different heads. I think they are off a corvette or a truck b/c they didnt have all the bungs to accept the whole pcv system. So I had to modify. Do you think if I got a newer style pcv system, that would at least cut down on the fumes? By the way, thanks for the input! 
If you can get a factory-style PCV system back on the car that completely takes all of the crankcase fumes back to the intake and is totally sealed then it will probably cut out most of the fumes you get, but not likely all of them. There are other variable like small header leaks or leaks from the purge canister that could also cause fumes. Most likely, though, the fumes you are getting are from the breather you have.
No cats will contribute to your smell as will running rich.
Most commonly from what I have seen and experienced, an exhaust leak is the problem if it's really strong.
The hood alone won't cause it but would exacerbate the problem if other factors are present.
Fighting the leak thing myself right now...
Hope that helps...
Most commonly from what I have seen and experienced, an exhaust leak is the problem if it's really strong.
The hood alone won't cause it but would exacerbate the problem if other factors are present.
Fighting the leak thing myself right now...
Hope that helps...
Well, the tune is ok, A/F is in the right place. Car isn't running rich. I know there will be a little smell all the time, but I just wanted some input to see if anything else could contribute. The pcv is definitely a problem that I need to address. My exhaust is all welded from the headers back b/c I did have leaks before and wanted to correct that. But this is different. I know the breather and pcv, now, is most of the problem. After I fix that, it should be much better. Thanks for the help though. I checked alot of this before, just finally got sick of dealing and want to finally fix it.
