Side Pipes stinking up interior
Thread Starter
Instructor
Joined: Jun 2011
Posts: 100
Likes: 1
From: Munich
Side Pipes stinking up interior
Hi Guys,
my side pipe exhausts seems to be circulating around my wheels and for some reason wind up in the interior of my C3. When TTops installed and windows closed, no fumes are noticed. When driving topless, it is really annoying.
Is there any fix for this issue? Personally, I hardly care, but I dont want my little girl to inhale the fumes when driving with me!
here's a pic...pretty standard pipes.
any help is highly appreciated!
cheers,
omar
my side pipe exhausts seems to be circulating around my wheels and for some reason wind up in the interior of my C3. When TTops installed and windows closed, no fumes are noticed. When driving topless, it is really annoying.
Is there any fix for this issue? Personally, I hardly care, but I dont want my little girl to inhale the fumes when driving with me!
here's a pic...pretty standard pipes.
any help is highly appreciated!
cheers,
omar
Team Owner
Joined: Sep 2006
Posts: 31,170
Likes: 4,245
From: Westminster Maryland
Hi o,
Does it seem to make any difference if the rear window is in or not?
I sometimes felt as though exhaust was coming through the rear window opening, not the side windows.
Regards,
Alan
VERY nice looking 69!
Does it seem to make any difference if the rear window is in or not?
I sometimes felt as though exhaust was coming through the rear window opening, not the side windows.
Regards,
Alan
VERY nice looking 69!
Race Director
Joined: Oct 2008
Posts: 19,143
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From: Long Island
There are 2 drains for the rear astro vent. The rubber hoses fall apart and the fumes can enter the car. Also the C3's (sugar scoop) tend to create a vacuum behind the rear window which can suck fumes into the rear of the car if the rear window seal is bad, again through the drain hose.
The hoses run from the bottom of the rear astro vent box to the top of each wheel well.
Both my 71 and 72 had bad hoses / tubes. The 72 leaked water into the interior due to the ripped clogged tubes.
It's a low mile car but the tubes / hoses just deteriated and split.
Last edited by BLUE1972; Apr 19, 2015 at 11:28 PM. Reason: spelling
Thread Starter
Instructor
Joined: Jun 2011
Posts: 100
Likes: 1
From: Munich
thanks so much guys. highly appreciate it!
Allan, rear window on/off makes no difference at all. neither does the velocity, which made me thinking perhaps its coming through some hole in the fire panel (from the engine compartment). However, with tops on and windows closed, everything is fine so it cant be that.
bellaireroad, by carb you mean carburator, right? sorry, my english sucks when it comes to tech talk. if it is the carb, wouldn't the fumes be coming in from up front?
BLUE1972, I am wondering if you might be correct. I would have never thought about those vents and will check this weekend if the hoses are faulty.
thanks again guys, I love this forum!!!!!!
greetings from Germany!
omar
Allan, rear window on/off makes no difference at all. neither does the velocity, which made me thinking perhaps its coming through some hole in the fire panel (from the engine compartment). However, with tops on and windows closed, everything is fine so it cant be that.
bellaireroad, by carb you mean carburator, right? sorry, my english sucks when it comes to tech talk. if it is the carb, wouldn't the fumes be coming in from up front?
BLUE1972, I am wondering if you might be correct. I would have never thought about those vents and will check this weekend if the hoses are faulty.
thanks again guys, I love this forum!!!!!!
greetings from Germany!
omar
Race Director
Joined: Oct 2008
Posts: 19,143
Likes: 1,667
From: Long Island
ASTRO VENTALATION - the car is pressurized by the HVAC fan which exits through the rear vents unless you have a/c. On some years the fan has no off setting only low, this sucks air through the grille in front of the windshield and exits it into the car through the HVAC system. This was to prevent people from suffocating themselves from faulty exhaust.
If you have missing hood seals and a leaking exhaust flange you may smell exhaust in the car from exhaust blowing out the rear of the hood into the vent in front of the windshield. This is not that common.
The tubes are on each side and exit into the top of the wheel well, under a SS steel cover.
Last edited by BLUE1972; Apr 23, 2015 at 12:18 PM. Reason: spelling location
Thread Starter
Instructor
Joined: Jun 2011
Posts: 100
Likes: 1
From: Munich
Hi Guys,
I took my lady vette out today and specifically checked for the exhaust smell again. I drove and had roof on and windows closed: in this event, no fumes whatsoever.
The second I open the window, the fumes enter the cabin again. So the pipes must not be blowing the exhaust away from the car sufficiently. I just don't get it! If I look at hooker pipes and the 90 degree angle of the exit and compare this to my 45 degrees, perhaps this is the reason?
cheers,
omar
I took my lady vette out today and specifically checked for the exhaust smell again. I drove and had roof on and windows closed: in this event, no fumes whatsoever.
The second I open the window, the fumes enter the cabin again. So the pipes must not be blowing the exhaust away from the car sufficiently. I just don't get it! If I look at hooker pipes and the 90 degree angle of the exit and compare this to my 45 degrees, perhaps this is the reason?
cheers,
omar
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From: New Or-leens Loo-z-anna
Rookie question: Compared to other cars with sidepipes with the engines idling........does the exhaust pressure coming out of your sidepipes seem the same/more/less compared to the exhaust pressure of other cars sidepipes?
Maybe the baffles in your sidepipes are too restrictive and not blowing the exhaust far enough away allowing the fumes to enter the cabin. I would think that 45 degree exits would be better than 90 degree exits.
Even though it seems it's a "windows-down" problem.....
You could connect some type of air blower--an electric leaf blower to a window opening that has been sealed off with duct tape in order to build pressure in the cabin.....
then go around the car listening for "air leaks".....just to eliminate those possibilities of recirculating exhaust gas (since the cabin has a "semi-pressurized" atmosphere with the windows normally up it will not allow fumes into the car even with spots that might have air leaks).
Maybe the baffles in your sidepipes are too restrictive and not blowing the exhaust far enough away allowing the fumes to enter the cabin. I would think that 45 degree exits would be better than 90 degree exits.
Even though it seems it's a "windows-down" problem.....
You could connect some type of air blower--an electric leaf blower to a window opening that has been sealed off with duct tape in order to build pressure in the cabin.....
then go around the car listening for "air leaks".....just to eliminate those possibilities of recirculating exhaust gas (since the cabin has a "semi-pressurized" atmosphere with the windows normally up it will not allow fumes into the car even with spots that might have air leaks).
Last edited by doorgunner; Apr 24, 2015 at 03:55 PM.
Melting Slicks
Joined: Oct 2001
Posts: 2,062
Likes: 1,361
From: Halifax, Nova Scotia, Canada
Hi Guys,
I took my lady vette out today and specifically checked for the exhaust smell again. I drove and had roof on and windows closed: in this event, no fumes whatsoever.
The second I open the window, the fumes enter the cabin again. So the pipes must not be blowing the exhaust away from the car sufficiently. I just don't get it! If I look at hooker pipes and the 90 degree angle of the exit and compare this to my 45 degrees, perhaps this is the reason?
cheers,
omar
I took my lady vette out today and specifically checked for the exhaust smell again. I drove and had roof on and windows closed: in this event, no fumes whatsoever.
The second I open the window, the fumes enter the cabin again. So the pipes must not be blowing the exhaust away from the car sufficiently. I just don't get it! If I look at hooker pipes and the 90 degree angle of the exit and compare this to my 45 degrees, perhaps this is the reason?
cheers,
omar
I just checked with my wife and she verified that there are no smells.
(My wife can smell things that I can't even think of smelling)
There are no smells with the window open driving slow or fast, and no smells with the roof off, driving slow or fast.
The only time I get an odour is sometimes at a toll booth (stopped with window down and/or with roof off)
My exhaust runs quite rich, if idling inside the garage, with door open, the fumes will drive you out quickly.
So, I really don't see why you're getting the fume odours.
Thread Starter
Instructor
Joined: Jun 2011
Posts: 100
Likes: 1
From: Munich
Today I drove out again, this time taking out the rear window. Without the rear window and with the other windows up, it smells slighty more than with all windows closed, but it is acceptable.
So, here are the results of my "experiments":
- All windows closed, tops on: NO FUMES
- All windows open, tops off: LOTS OF FUMES
- Windows closed, rear window open: LIMITED FUMES
I am assuming the exhaust gets caught open in a turbulence around the rear wheels and get pulled up towards the windows (especially the side windows + somewhat the rear window).
If this is the case, there is not much I can do about it.
So, here are the results of my "experiments":
- All windows closed, tops on: NO FUMES
- All windows open, tops off: LOTS OF FUMES
- Windows closed, rear window open: LIMITED FUMES
I am assuming the exhaust gets caught open in a turbulence around the rear wheels and get pulled up towards the windows (especially the side windows + somewhat the rear window).
If this is the case, there is not much I can do about it.
2026 Loser of the Year
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From: New Or-leens Loo-z-anna
Today I drove out again, this time taking out the rear window. Without the rear window and with the other windows up, it smells slighty more than with all windows closed, but it is acceptable.
So, here are the results of my "experiments":
- All windows closed, tops on: NO FUMES
- All windows open, tops off: LOTS OF FUMES
- Windows closed, rear window open: LIMITED FUMES
I am assuming the exhaust gets caught open in a turbulence around the rear wheels and get pulled up towards the windows (especially the side windows + somewhat the rear window).
If this is the case, there is not much I can do about it.
So, here are the results of my "experiments":
- All windows closed, tops on: NO FUMES
- All windows open, tops off: LOTS OF FUMES
- Windows closed, rear window open: LIMITED FUMES
I am assuming the exhaust gets caught open in a turbulence around the rear wheels and get pulled up towards the windows (especially the side windows + somewhat the rear window).
If this is the case, there is not much I can do about it.
How about attaching two small air foils to the frame the width of each tire to scoop up undercarriage airflow and direct it up and over the tires, They would only have to be spaced an inch lower than the frame/wouldn't even be noticeable.
Thread Starter
Instructor
Joined: Jun 2011
Posts: 100
Likes: 1
From: Munich
How about attaching two small air foils to the frame the width of each tire to scoop up undercarriage airflow and direct it up and over the tires, They would only have to be spaced an inch lower than the frame/wouldn't even be noticeable.[/QUOTE]
Don't quite understand what you mean.....I made some pics of the exhaust pipe and am thinking, if the pipe itself may have some holes. Will check tomorrow. Are you talking about air foil at the yellow or red arrow? In any case, it would definately look ugly....
Don't quite understand what you mean.....I made some pics of the exhaust pipe and am thinking, if the pipe itself may have some holes. Will check tomorrow. Are you talking about air foil at the yellow or red arrow? In any case, it would definately look ugly....
Melting Slicks
Joined: Jan 2014
Posts: 2,478
Likes: 254
From: Downers Grove Illinois
I think one of your pipes may have a small leak under the car. When you drive with everything closed there is a little pressure caused by the blower motor so no exhaust gets in. When you open the windows or take off the tops and drive you are creating a low pressure area in the car and sucking fumes in. If you are in an open area with little or no wind and have the windows open and the car running do you smell the fumes?
Thread Starter
Instructor
Joined: Jun 2011
Posts: 100
Likes: 1
From: Munich
Man, that is gonna cost me a fortune to have new pipes shipped over here....
Burning Brakes
Joined: Jan 2006
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From: Clear Lake Shores Texas
2016 C3 of Year Finalist
I think one of your pipes may have a small leak under the car. When you drive with everything closed there is a little pressure caused by the blower motor so no exhaust gets in. When you open the windows or take off the tops and drive you are creating a low pressure area in the car and sucking fumes in. If you are in an open area with little or no wind and have the windows open and the car running do you smell the fumes?
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From: New Or-leens Loo-z-anna
Now that I see the pics.....scratch the airfoil idea. How about a couple of large brushless exhaust fans similar to those used in electronic cabinets mounted in the rear panel of the storage compartment...they could be low-amp fans that pull enough cfm to draw the fumes away from the seats and then exit to the rear of the car.....just wondering out loud since the current ventilation fans works with the windows up.
[/QUOTE]Those are great-looking sidepipes!
I wouldn't want you to spend un-necessary money on new pipes....maybe bad sections of your current pipes could be replace to see if the internal baffles are causing restrictions to the exhaust flow
Last edited by doorgunner; Apr 25, 2015 at 04:14 PM.
Team Owner
Joined: Jul 2004
Posts: 40,338
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From: Redondo Beach, California
Not helping out with the problem...my apologies. I have factory sidepipes on my 68 convertible. The were bought in the late 1970's from GM parts. They still look like new..no blemishes. I'd just so much love to drive one of my Corvettes on the German autobahn!
....................
OK, If you really want to check this out. Maybe try taping little pieces of 4 inch yarn on the body of the car around the exhaust pipes. Driving at speed have a friend look at the pieces of yarn. They will show air flow over the body of the car. This should give you a visual idea about airflow out of the exhausts around the car body. Don't know what the German word for yarn is...it's the stuff people weave to make sweaters. (stuff is good german/english word!!) If you buy a Robertson turbine Helicopter ($750,000), the canopy has two yarn strips on the outside! If the yarn strips are pointing upward...it means you are descending and have a problem! I think some of the pre-WWII biplanes used to have yarn pieces in the airflow for the pilot to look at. The basic message here is that yarn strips are cheap and very indicative of air flow.
....................
OK, If you really want to check this out. Maybe try taping little pieces of 4 inch yarn on the body of the car around the exhaust pipes. Driving at speed have a friend look at the pieces of yarn. They will show air flow over the body of the car. This should give you a visual idea about airflow out of the exhausts around the car body. Don't know what the German word for yarn is...it's the stuff people weave to make sweaters. (stuff is good german/english word!!) If you buy a Robertson turbine Helicopter ($750,000), the canopy has two yarn strips on the outside! If the yarn strips are pointing upward...it means you are descending and have a problem! I think some of the pre-WWII biplanes used to have yarn pieces in the airflow for the pilot to look at. The basic message here is that yarn strips are cheap and very indicative of air flow.
Last edited by 68/70Vette; Apr 25, 2015 at 08:08 PM.
Race Director
Joined: Oct 2008
Posts: 19,143
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From: Long Island
What is the condition of you rear Astro drain tubes?
If exhaust gets into the wheel well, and the tubes are ripped it will enter your car.
One other area is the plug for the rear wire harness and antenna, upper left (driver) are in the rear.
If exhaust gets into the wheel well, and the tubes are ripped it will enter your car.
One other area is the plug for the rear wire harness and antenna, upper left (driver) are in the rear.