Exhaust coming in vent
 

Can anybody tell me why exhaust would come into my car via the vents
when I start it up cold? It only happened once and that was today. My
friend and I got in and started it and the exhaust just poured in. Any
reason why this would happen?

Also...just to clarify, it looks like it only came through when I had
it set on the chest level vents (not sure if there's a technical name
for them). That's where it was most obvious, at least. And it only
came in for about a minute and then stopped. I just bought this car a
month ago and it was inspected and everything. What's strange is that
the exhaust system was done, so this shouldn't be happening already.

That sounds like you had it on vent for fresh air and for sure the
exhaust has a major leak in it pointing right at the air intake or the
wind was blowing just right.

The trouble is the part of exhaust that kills has no smell so you are
lucky you got a warning before something bad happened. Watch really
carefully for symptoms like a forehead/sinius appearing headache or
unusual drowsiness.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

Son of Sam wrote:
>
> Also...just to clarify, it looks like it only came through when I had
> it set on the chest level vents (not sure if there's a technical name
> for them). That's where it was most obvious, at least. And it only
> came in for about a minute and then stopped. I just bought this car a
> month ago and it was inspected and everything. What's strange is that
> the exhaust system was done, so this shouldn't be happening already.

Can you tell me how to spot this leak? Are they easy to detect?

Thanks for the information. I'll definitely be watching for these
warnings. Is it possible though, for one to not smell anything but
still be getting carbon monoxide poisoning or something?

Son of Sam wrote:
> Can you tell me how to spot this leak? Are they easy to detect?
>
> Thanks for the information. I'll definitely be watching for these
> warnings. Is it possible though, for one to not smell anything but
> still be getting carbon monoxide poisoning or something?

Don't just watch for those symptoms. For the sake of your safety and
that of other drivers who would be endangered if you pass out behind
the wheel, please get your exhaust system checked and repaired right
away. It's not worth the risk to wait it out.

Yeah, I'll do that. I'll look in my manual, to see if I can figure it
out because I can't afford to take it into a shop right now.

The symptoms are extremely sneaky. A friend couldn't understand how
come he couldn't stay awake for highway driving until I drove with him
and realized the soft top on with no windows in it was a CO trap. No
smell at all but I got that headache right away. Once he realized he
had to have the front door windows open as well, we were ok.

You can use an old chunk of garden hose or some other tube and hold one
end to your ear while moving the other end around the manifold area.
Inspection techs have a stethoscope type thing for doing that.

If the exhaust is recently new, I would be suspecting the fitting where
the manifold hooks to the pipe as being a likely place something came
loose or shifted causing a leak. Black streaks are also a give away.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

Son of Sam wrote:
>
> Can you tell me how to spot this leak? Are they easy to detect?
>
> Thanks for the information. I'll definitely be watching for these
> warnings. Is it possible though, for one to not smell anything but
> still be getting carbon monoxide poisoning or something?

Son of Sam wrote:
> Can anybody tell me why exhaust would come into my car via the vents
> when I start it up cold? It only happened once and that was today. My
> friend and I got in and started it and the exhaust just poured in. Any
> reason why this would happen?


The car under discussion is an older Volkswagen or Porsche, I take it?

AFAIK, most all of the air cooled Volkswagens and Porsches had sheet
metal cowling around the heads to direct the heated air into the
cabin. A crack in the exhaust manifold might leak during warmup....

--Winston

Winston wrote:

> Son of Sam wrote:
>
>> Can anybody tell me why exhaust would come into my car via the vents
>> when I start it up cold? It only happened once and that was today. My
>> friend and I got in and started it and the exhaust just poured in. Any
>> reason why this would happen?
>
>
>
> The car under discussion is an older Volkswagen or Porsche, I take it?
>
> AFAIK, most all of the air cooled Volkswagens and Porsches had sheet
> metal cowling around the heads to direct the heated air into the
> cabin. A crack in the exhaust manifold might leak during warmup....
>

Actually not really. Those cars did have the cowling you describe, but
that was only for engine cooling. Then there were "heat exchangers" -
basically a tubular header with sheetmetal wrapped around THOSE - that
took warm air from the engine cooling tin and heated it more and then
ducted *that* up to the front of the car through the rocker panels.
Kickass heat when it worked, but obviously if the heat exchangers rust
out you're directly ducting fresh exhaust into the passenger
compartment. Not Good. Fortunately, at least for Porsches, stainless
steel heat exchangers are available (for a price...)

nate

ObShamelessPlug - I have a set of 914 stainless heat exchangers sitting
in my parents' barn, if anyone is interested they come with a 99%
complete parts car as well - see my website if I've piqued your interest.


--
replace "fly" with "com" to reply.
http://home.comcast.net/~njnagel

"Son of Sam" wrote

> Can you tell me how to spot this leak? Are they easy to detect?

Start the car. Have your buddy hold a towel or thick rag firmly over the
tailpipe(s) to build up some pressure. Not TOO tight... don't want the
muffler(s) to explode. :)

Listen for whistles or similar noises where the exhaust is leaking out.
If you can reach, hold your hand near the various joints and feel for a
rush of exhaust from the leak.

Don't burn yourself, and stay away from moving parts (fan, belts).