2001gti exhaust leak
- Thread starter Daveegt
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Sportster-2001-951C-Stock
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I'm thinking one of the exhaust pipe welch plugs is corroded through, these are aluminum plugs welded in place after casting the manifold.
It might also be a case of water trapped in the pipe during winter froze, expanded and cracked the pipe?
Sad story, A guy brought his boat by here just today said he parked it over winter and neglected to winterize and forgot to remove the drain plug. Motor was sitting under water all winter which may have saved it from freeze cracking, I'm sure the result won't be good... ugh!
It might also be a case of water trapped in the pipe during winter froze, expanded and cracked the pipe?
Sad story, A guy brought his boat by here just today said he parked it over winter and neglected to winterize and forgot to remove the drain plug. Motor was sitting under water all winter which may have saved it from freeze cracking, I'm sure the result won't be good... ugh!
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I just started it on the trailer and the exhaust seems to be coming from the back. I reached back as far as I could to the outlet rubber hose. It is VERY soft, I can squeeze it almost flat. My arms aren't long enough to feel the back. Could it have burned a hole thru it? If so is this any way normal? Is the exhaust cooled with water spray in the header to keep the rubber cool?
Sportster-2001-951C-Stock
Well-Known Member
Yes, water must be mixed with exhaust just after leaving exhaust manifold, water is injected in two locations to avoid unsafe heated objects in the bilge. If the exhaust cooling water injection is disrupted (clogged cooling line or device) water injection will be insufficient to keep exhaust components from becoming unsafely hot, rubber hoses and plastic exhaust parts will melt as well.
Also over the decades, rubber hoses will rot and delaminate due to hydrocarbon chemistry and the natural deterioration of rubber components, it's a pretty harsh environment thus water injection into the exhaust stream helps cool and keep things from becoming "unglued".
Also over the decades, rubber hoses will rot and delaminate due to hydrocarbon chemistry and the natural deterioration of rubber components, it's a pretty harsh environment thus water injection into the exhaust stream helps cool and keep things from becoming "unglued".
Mickirig1
Well-Known Member
You can do a engine running test with it still on the trailer. Back it down a lake ramp enough to have the intake grate under water. Still securely tied down on the trailer. Start it up and let run. Feel the exhaust components for heat after 5 min. They should be just warm. look for the exhaust leak. Check all the cooling lines. I had a small one, with a hole in it where I could not see it. Filled hull with water about 2 inches. Tuned pipe ran hot. The Welch plugs are welded in to cover casting holes. The corrode thru all the time. A high school welding shop can fix it cheap. Or a professional welding shop.
I have had mine done for $50 each pipe at my Wife's high school. The tuned pipe can be $700 - $1,000 if you can find one.
I have had mine done for $50 each pipe at my Wife's high school. The tuned pipe can be $700 - $1,000 if you can find one.
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