Exhaust problems....
06-28-2003, 08:14 PM
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Exhaust problems....
It sounds like i have a leak somewhere in the exhaust, somewhere between the engine and the cat converters...replaced the manifold to tailpipe gaskets but it seems to have done nothing. another problem, i don't know if its related at all, but it get a weird, almost backfiring sound when i use the engine to slow me down. if anyone has any suggestions of what to try/do it would be most appreciated. thanks.
06-28-2003, 08:27 PM
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My A4 has suffered from exhaust farts since the beginning
They occur usually when getting off the gas, especially when coasting downhill. The car has done this from day 1 (And so have the two VW cars I've had). According to the dealer it's a "normal exhaust noise"... Quite frankly, after 125k miles I've come to accept that noise, though, I'd love to know what causes it.
I wonder if it might be related to the EGR valve.
I wonder if it might be related to the EGR valve.
06-28-2003, 09:03 PM
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All the time, or only when cold? When cold it's normal for my car, but . . .
It has never occurred after the exhaust system has heated up. A piping hot exhaust system should not make popping noises according to an AW post I read a long time ago regarding this issue. It's due to how the exhaust system gets rid of water after it has condensated in the exhaust system after cool down. Thus, it should only occur after the exhaust system has cooled and while it remains relatively cold.
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06-28-2003, 09:43 PM
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I have no idea!
I'm still using the original exhaust after almost 7 years. Looks like the damn thing lasts forever - not that I'm complaining. I know NOTHING about exhaust systems!
06-28-2003, 10:22 PM
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From what I remember, it has nothing to do with leaks . . .
Perhaps the moist air conditions you have up there in the Bay area cause more water to get into the exhaust system. In So. Cal., the air is so dry here, I hardly ever see water coming out of my tail pipe.
Additionally, I use a fuel catalyst that (among a miriad of other things) reduces fuel's tendency to absorb water. I do not know whether it helps with the popping noises in the exhaust, but it may.
Here's a theory: if the water in your exhaust system condensates to form water droplets rather than remains a vapor and if that water rolls down in the opposite direction because the car faces down hill and you have allowed it to engine brake, when it hits a hot spot, I can see it popping like dripping water on to a hot frying pan. It could be that you exhaust gases cool too quickly and allow water to condensate or that the heat gets trapped at some point in your exhaust system. How hot does the exhaust feel at the tail pipe?
Additionally, I use a fuel catalyst that (among a miriad of other things) reduces fuel's tendency to absorb water. I do not know whether it helps with the popping noises in the exhaust, but it may.
Here's a theory: if the water in your exhaust system condensates to form water droplets rather than remains a vapor and if that water rolls down in the opposite direction because the car faces down hill and you have allowed it to engine brake, when it hits a hot spot, I can see it popping like dripping water on to a hot frying pan. It could be that you exhaust gases cool too quickly and allow water to condensate or that the heat gets trapped at some point in your exhaust system. How hot does the exhaust feel at the tail pipe?