Exhaust leak noise
#1
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i posted this once before but still chasing this noise. It sounds like a exhaust leak at the head under a load at low rpms but I don’t see any burn marks around the header flange. No ticking at idle. Second gear low speed under a medium load and this terrable sound almost like one cylinder is leaking exhaust. Don’t see anything around the flange or collector. It did it with corsa cans and no cats and now I have stock NPP cans still no cats and it still makes that noise.
#2
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Almost sounds to me like you are hearing the lifters or valvetrain. I can hear valvetrain at slow speeds in 2nd gear when cruising around the city streets. Even after doing my heads.
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this sound only happens when you are on the gas at low rpms and you have the engine under a load. It’s most apparent in second gear. It’s loud and has a glass pack muffler sound but coming from the engine area. Thought it was because I was not running cats but I talked to others who don’t have them and they don’t have this sound.
#4
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I use a stethoscope with an open tube to probe for that type of sound. A piece of vacuum hose on the end works pretty well. Probe around the flanges, it'll pick up minor exhaust leaks pretty well.
#5
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In fact, I think Harbor Freight sells an inexpensive one for like $5.
OP, you have LT's?
Last edited by MTPZ06; 02-05-2019 at 05:23 PM.
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I did the test with the vacuum blowing in the exhaust pipe and spraying soapy water on the leaking area. It was foaming bubbles everywhere. I read that the GM gasket was the best but when I removed the gasket it was the same GM ones I ordered. I didn’t see much burn marks around the head. Is there a better gasket.
#7
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I feel stupid. The noise I’ve been hearing was the shifter clicking. I heard the noise today and I happen to have pressure on the shifter and I could feel the clicking in the handle. I made it so it again and I pulled the shifter toward me and the noise quit. It’s the damn shifter all this time. Can’t believe I didn’t know this before.
#8
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I did the test with the vacuum blowing in the exhaust pipe and spraying soapy water on the leaking area. It was foaming bubbles everywhere. I read that the GM gasket was the best but when I removed the gasket it was the same GM ones I ordered. I didn’t see much burn marks around the head. Is there a better gasket.
