Exhaust Fume Incursion into Passenger Compartment

[Bobpantax]

Please do not respond to this post if you are not capable of giving a simple yes or no answer. The post is not for any hidden purpose. There is no hidden agenda. It is not litigation research. Thank you in advance for limiting your response to the issue. The issue is as follows:

It is common for 1992 - 2002 Vipers to experience exhaust fume incursion into the passenger compartment due to dislocation of one or both of the rear vents located to each side of the rear deck area. There have been prior posts on this problem including how to fix it. I think that it is important to determine the scope of the problem since exhaust fume incursion, which is not always noticeable and includes Carbon Monoxide is a very serious matter. PLEASE POST IF YOU HAVE HAD THE PROBLEM. Thank you.

 

[Fast Freddy]

yes, i have this problem but it only presents itself when my windows are open. when my widows are closed this never happens. therefore i come to the conclusion that the exhaust is not coming thru the rear of the car but the side windows when they are cracked or down. oh yea, one more thing my year 2001 viper acr has rear exit exhaust. i bet if i were to convert my car to side pipes like the original GEN 1 vipers were designed for, this problem would eliminate itself. i have always liked the look of the side exhaust system and i am considering doing this in the future. i just don't care much for the sound of the lack of H-pipe on a non srt-10 side pipe car. but then no cats and increased compression ratio with a big nasty cam should mitigate that (no pun intended, lol).

the exhaust problem in my car is so bad that on long trips with my windows down i get headaches and my wife does not want to ride in the car with me because she gets sick. i took my car to lou bellanger in phoenix, arizona who designed, engineered and installed my headers; and installed my random tech cats and corsa cat back exhaust system. i told him that i thought there was a leak in the system. he put the car on the lift and pulled my side panels off and thoroughly checked everything out and told me that there are no leaks. he then proceeded to tell me that corsa's exhaust sytem stops shorter at the rear of the car then his system by about 2 inches and that if i would have bought his cat back system that i would not have this problem. he said that the exhuast is not coming thru my rear vents but is coming thru my side windows like i have explained in the previous paragraph. lou bellanger told me that in wind tunnel testing of the vipers body shape there is a low pressure area on the rear quarter panels of the viper that creates a venturi effect in the airflow of the car in this area. unfortunately as a result the exhaust back channels its way across this area of the car thru the side windows as result of this swirling effect. this is most certainly true as i have thoroughly tested and researched this on my car. it happens at speeds below 100 mph only though because at speeds above 100 mph the airflow dynamic changes and as result of the subsequent changes in airflow dynamics at that speed the reversion of the exhaust into the cab is prevented. the funny thing is i never recall having this problem with my stock unmodified exhaust system.

with all this said, i will begin road racing my viper next year and the organizations with which i will be racing my viper require that i race with my windows down and a window net. i am concerned that the fumes could cause me to pass out! seriously!! i am not joking!!! at my local paved oval track raceway where i live i watched a stock car driver pass out in his car and hit the wall. the reason he passed out was because the exhaust system in his race car had a leak and was ventilating the exhaust into his drivers compartement while he was racing.

 

[TOOOFST]

Some style headers gaskets leak after some time.I recently replaced mine after 2yrs and the fumes are gone.

 

[GTS Bruce]

Ok Bob.You drop the lawyer stuff and we will play nice too.I have never had a problem with my 01 GTS with the windows closed.Possibly because I keep the blower on and turned to high to prevent my headers from melting the blower airbox.Never a problem even on a 7-12 hour drive.Not a problem windows down while moving along.However stopped or in stop and go with the windows down I can smell it because I have no cats.Try Just turning the HVAC blower up and leave it on with the windows up.Maybe positive cabin pressure has made a difference for me. GTS Bruce

 

[Andrew/USPWR]

Never had a problem smelling any fumes.


Unless I had Mexican for lunch.

 

[LETHAL GTS]

Yes I do, but only when my windows are partly down or one is a crack open while cruising at legal speeds. When my windows are up.....nothing. When my windows are all the way down, which is how I normally have them, nothing until I come to a stop or going quite slow. I have been worried about this and I too though maybe I had an exhaust leak since I've changed header and exhaust. However I used new gaskets and Vclamps to prevent an exhaust leak. After inspecting those areas I found them to be leak free. So I chalked it up to aerodynamics of the car.
I only drove my car once with the stock exhaust system on. So I can't comment on that.

 

[pdmracing]

I have a stock exhaust & my car has done this from new, @ low speeds with the window (one or the other) open

 

[Bernard]

I had side pipes put on my 2000 RT/10 and yes, I do smell exhaust fumes. I have never seen or heard of anyone with a similar setup passing out on the track or street.

 

[Schulmann]

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Please do not respond to this post if you are not capable of giving a simple yes or no answer. The post is not for any hidden purpose. There is no hidden agenda. It is not litigation research. Thank you in advance for limiting your response to the issue.

Bobpantax,
I think you are likely the best lawyer in Florida. The way you turn your phrases ... If I have the bad luck to get in trouble with justice in Florida I will call.

Yes, some times I have smoke or rather fuel smell in the cockpit when my car idles. This due to my race setup. The only way to get around is to roll above 5mph. The fume is coming from the engin compartment and not from the exhaust

There is NO WAY to smell that you have Carbon Monoxide in your car. Carbon Monoxide is odourless. You just fall asleep and never wakeup ....

 

[dblankenbaker]

It is common for 1992 - 2002 Vipers to experience exhaust fume incursion into the passenger compartment due to dislocation of one or both of the rear vents located to each side of the rear deck area.

I don't believe this, as I have driven and ridden in numerous Vipers over the last 10+ years and I have only smelled exhaust fumes then the windows have been open (or top off).

 

[Peter-RedGTS'98]

Only when accelerating rapidly and windows are down.

 

[AviP]

Never in my GTS, windows up or down. Never smelt/seen any CO2 which is usually the hint for some CO in the area.

 

[thebigsnake]

Hey ***** waist. Its a Viper, not a Maybach.

 

[AviP]

Hey ***** waist. Its a Viper, not a Maybach.

I'm waiting to hear the lawyer jokes.

 

[Bobpantax]

Here is the technical explanation of the issue. The issue is real. It does occur frequently in Vipers. The incursions some of you have described are not from the engine compartment. The fumes are probably due to the rear "Exhauster" vents being out of place or the rubber in the vents having deteriorated to a state where there are gaps or holes. The incursion should be worse while standing still, on deceleration, and/or with the AC on re-circulate. See the Viper Service Manual, body section 23 and look at the picture and the instructions. Most Viper owners do not know that the exhauster vents are present in their vehicle. Their purpose, at least in the GTS ( I am not sure that they are in the RT 10 and, if they are not, I correct the model years to 1996 through 2002 for the GTS only), is to allow for the release of air when the rear glass deck lid is closed. They are only supposed to operate one way - out. Air/ exhaust is not supposed to be able to come into the vehicle. I suggest that each of the skeptics ( a generous term to describe the less than appropriate responses) take the time to educate themselves as opposed to giving an unmedicated adult attention hyperactivity disorder response that too frequently occurs on this board. Such responses are immature, unresponsive, and do nothing to help further the lot of fellow Viper owners.

 

[DrDJ]

I have never had any fumes in the two GTSs I have owned. This is, however, an interesting bit of trivia. Why didn't you post it in the first place and save us all the drama?

 

[Bobpantax]

See above. It was posted here. It was also posted in the prior thread that was hijacked and converted into a personal diatribe by someone who hates lawyers. I feel sorry for the fellow but the purpose of this forum is to share information about Vipers.

 

[hemibeep]

These parts are two pieces. The "louvers" are plastic a resemble old jalousy(sp) windows with small flaps of rubber that are gravity closed. then there is a larger rubber cover that is attached on three sides with a double stick tape.
On my car, with the accident, they were not working correctly, result of impact or air bags?, I don't know. I never thought of fumes, just of water leak. It is obvious that exhaust could find its way to these flaps as my bumper is always covered with exhaust type "residue".
Perhaps someone who feels concerned could try a CO2 dectector inside the car to check???

 

[Bobpantax]

Good post. I found that my right side did not have the rubber cover at all! I suspect that since the area is so tight, a number of rubber covers may have been left off during original assembly. A good experiment if someone has the smell of fumes inside their vehicle is to pull back the carpeting away from the vents. Then cut out some cardboard big enough to cover each vent. Place some tape around the perimeter of each piece of cardboard and then completely cover up each vent. Then put back the carpeting. Be sure to leave one of the door windows open a little before closing the glass deck lid so air has a way out. If the smell is reduced or eliminated, you have found the cause.

 

[Mark Red GTS Cooper]

All,

Do a search on this. I just went through this! It was the vent flaps.

They are a pain to get in a and out, but I bet 100% that it is the vent.

Most likely it shifted, or the flaps are stuck open.

Mark

 

[Eric H]

Actually the air flaps are there to release the pressure inside the cabin if the airbags deploy with the windows closed. The pressure caused by not venting the air inside the cabin when the airbags deploy would likely burst you eardrums.

EVERY car on the road has these flaps in the rear of vehicle.

And no, i have never had this isse, at least not to my knowledge. As stated before Carbon Monoxide has no smell.


The reason you dont get the fumes in the car with the windows up is the Air blowing from the AC/heat blowing causes positive pressure in the cabin that keeps the exhaust out. when the windows are down the air rushing over the sides of the car causes a vaccuum inside the car similiar to the Bernoulli principle that makes airplanes fly

blah blha blah

 

[Bobpantax]

Interesting. However, the main concern is not Carbon Dioxide. The main concern is Carbon Monoxide. Over twenty percent of the air we breath is Carbon Dioxide. Carbon Monoxide binds with hemoglobin and displaces oxygen. Also, as stated above, when you put the AC on recirculate ( the windows would be closed ) and the exhauster vents are broken so that they function on a two way basis instead of a one way basis, exhaust is drawn into the vehicle through the vents. The exhauster vents ( there are two on each side inset into a metal framework) can be out of place; the rubber louvers can be torn, or otherwise deteriorated; and/or the rubber cover can be missing, fallen off or not attached properly. The experiment I suggested above works for those who think they have a problem. The next issue is replacement of the exhauster vents and flap - not easy because the metal frame is riveted into place with plastic rivets instaed of bolted or screwed into place. In my opinion this was penny wise and pound foolish engineering.

 

[Eric H]

yeah yeah, thats what i meant...edited as such.


even on recirclate the cabin maintains positive pressure so no or minimal exhaust should enter unless air is leaving somewhere, ie........leaking out the windows or doors. granted the cars arent airtight.....

My opinion as to the problem.....one, the car has a lot of power and anyone who drives it hard knows the flexing and forces the car is under, combine that with the sheer speed, how many honda civic do you see on the track doing 160+mph. so there are many forces at work that can cause the rubber flaps to dislodge, if its broke, fix it, dont expect DC to take the blame

 

[Bobpantax]

The AC recirculate phenomenon is well documented. The problem can arise without hard driving. The asembly is cheaply constructed and rubber can deteriorate over time. Some of the recent posts on this thread have been productive and informative. That is what this forum is for -to share information. Posters have very diverse and different skill sets and knowledge levels. You may not need to know about this issue and perhaps you have the technical skill to fix the problem yourself. However, many on this forum have little knowledge and even less technical skill. Since this subject appears to be beneath your skill level and experience perhaps you should direct your efforts elsewhere.

 

[V10TT]

Can someone post a picture of these vents?

 

[joemcmillen]

Have a severe exhaust fume problem in cabin when windows are open. Looked at the air exauster vent and the top drivers side vent is dislodged. I will fix it and see if the fumes susbide.

 

[Solid Red 98]

I only get fumes when I pin it once or twice with the windows down, but the fumes go away quickly and I forget about it--maybe its the fumes....

 

[KNG SNKE]

I have it bad but my vents are all shut.

 

[Doug Supercharged Vipers]

It's one thing to implement a better flap to restrict incoming exhaust gases. But be careful not to seal them off completely; among other essential reasons for the presence of the flap, you can also blow out the rear window glass at speed.

 

[Red Snake]

Blah, blah, blah....... PLEASE POST IF YOU HAVE HAD THE PROBLEM. Thank you.

NO



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