How do ya detect an exhaust leak?
Thread Starter
Melting Slicks
Joined: Mar 1999
Posts: 3,326
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From: Taylor TX
NCM Sinkhole Donor
How do ya detect an exhaust leak?
Under light acceleration in my A4 C5, I hear what sounds like an exhaust leak from the front half of the car. How can I really find out?
Melting Slicks
Joined: Jul 2000
Posts: 2,483
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From: Wilmington DE
Re: How do ya detect an exhaust leak? (lotzahp)
I think my first reaction would be to check every bolt on the exhaust system for tightness and visually inspect everything to make sure there are no holes. If the suspected exhaust sound continues, then back to the shop to see if they can find the suspected leak. Just be sure the sound isn't something else before going to all this trouble. :D
Melting Slicks
Joined: Aug 2000
Posts: 2,248
Likes: 1
From: Newland US
Re: How do ya detect an exhaust leak? (lotzahp)
lotzahp,
I'd follow Jim 47's advice first....then if you still suspect an exhaust leak....you might "smoke it out" like we did in the old days.
Prior to catalytic converters and oxygen sensors, we would squirt #2 diesel fuel down the throat of the carburetor which woul make it smoke like a biotch and then look so see if there was any smoke noted coming out of leaks.
Can't very well do the above today, but I don't know why you couldn't squirt some GM approved top engine cleaner past the butterflies in the Throttle Body(car not running)....reinstall the intake....start her up and check for leaks.
I had the metallic diaphram burn up in one of the AIR check valves on an LT1 engine and the exhaust pressure blew the hose off and gave an exhaust leak.
You might want to consider a possible bad check valve.....however if one were bad, I'd think you would get a code. Have you checked for codes?
Good luck.
Mark
I'd follow Jim 47's advice first....then if you still suspect an exhaust leak....you might "smoke it out" like we did in the old days.
Prior to catalytic converters and oxygen sensors, we would squirt #2 diesel fuel down the throat of the carburetor which woul make it smoke like a biotch and then look so see if there was any smoke noted coming out of leaks.
Can't very well do the above today, but I don't know why you couldn't squirt some GM approved top engine cleaner past the butterflies in the Throttle Body(car not running)....reinstall the intake....start her up and check for leaks.
I had the metallic diaphram burn up in one of the AIR check valves on an LT1 engine and the exhaust pressure blew the hose off and gave an exhaust leak.
You might want to consider a possible bad check valve.....however if one were bad, I'd think you would get a code. Have you checked for codes?
Good luck.
Mark
Racer
Joined: Oct 2001
Posts: 285
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From: Mountaintop PA
Re: How do ya detect an exhaust leak? (lotzahp)
A good way to detect an exhaust leak is to get the car on a lift. You will need two of your budies... Start the car, have each of your friends use a rag and cover both exhaust tips for a few seconds at a time. They have to do it in unisen and not more than a few seconds at a time. You can then walk along the exhaust system listening for the leak. Not high tech but it will locate a tuff to find exhaust leak. Remember, do not keep the exhaust covered for more than a few seconds at a time...
Team Owner
Joined: Nov 2000
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From: Central Florida
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St. Jude Donor '03-'08
Re: How do ya detect an exhaust leak? (jrd)
I had the same problem on 2000 A4 Coupe - it sounded like it came from the driver side of the headers.
I ended up replacing the entire exhaust system with an aftermarket Borla system - at the dealers advise - and guess what - I still had the sound. Mine was a fluttering sound that came from the engine under light to medioum acceleration. It would not happen when the car was at idle or cruise and it would not happen when you revved the engine. The car had to be in gear and driving in order to hear it. I ended up taking it to another dealer and he replaced the heads on the driver side. Guess what - still had the problem. I ended up saying the hell with it and traded it in on my Z06. Cost me over $1400 and never solved the problem.
I ended up replacing the entire exhaust system with an aftermarket Borla system - at the dealers advise - and guess what - I still had the sound. Mine was a fluttering sound that came from the engine under light to medioum acceleration. It would not happen when the car was at idle or cruise and it would not happen when you revved the engine. The car had to be in gear and driving in order to hear it. I ended up taking it to another dealer and he replaced the heads on the driver side. Guess what - still had the problem. I ended up saying the hell with it and traded it in on my Z06. Cost me over $1400 and never solved the problem.
Thread Starter
Melting Slicks
Joined: Mar 1999
Posts: 3,326
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From: Taylor TX
NCM Sinkhole Donor
Re: How do ya detect an exhaust leak? (joecooool)
it sounded like it came from the driver side of the headers....a fluttering sound that came from the engine under light to medium acceleration. It would not happen when the car was at idle or cruise and it would not happen when you revved the engine. The car had to be in gear and driving in order to hear it
Thanks Joe.
Melting Slicks
Joined: Jul 2000
Posts: 2,651
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From: redlands,ca.-usa
Re: How do ya detect an exhaust leak? (Pepper)
A easy and inexpensive way to check for a exhaust leak is to use a piece of 3/8--1/2 inch hose-Hold one end to suspected area and the other end to your ear-The sound will really jump out to you when you find it.
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