I think i might have an exhaust leak

94GTMOOSE

Member
Jun 27, 2005
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jersey shore
When i started my car lastnight it sounded like a old chevey. It was late and i didn't want to bother lookin at it so today i started it and it sounded like a old chevey again. I opened the hood and the sound is definly coming from the left side. i looked to see if i could see any exhuast fumes coming out, and didn't see any.

will an exhuast leak go away when the motor is warmed up? when i drove it around for a little bit i didn't hear it as much as i did when i first started. I think it might be the header. If so i think i am going to save my money and get a new set and change them now. I am thinking cheap, maybe BBK shorty chrome or if anyone here has a set for sale. I only have little bit to spend so i can't go all out. but first i have to figure out if its an exhuast leak first.

Is there any other things i should look for?
 
I can't help you with what to look for but if you purchase headers.......DO NOT go cheap......when I was doing my TFS build I bought generic 302 headers...had to cut and weld a inlet for the egr...and ended up braking a bolt off in my new aluminum heads......had to tap it out
I bought bbk shorties for 120.00/140.00- and they bolted up perfectly...my 2 cents
 
exhaust leaks can be somewhat hard to isolate as you generally have to have the engine loaded to hear it.

best thing i can say is put it in 4th gear at 1200rpms and give it gas gradually. if the noise gets louder with throttle application then it is an exhaust leak. if it stays constant--irrelevant to throttle--then it is most likely not.

you can try changing gaskets before you jump into buying a new set of headers, or maybe you just gotta loose bolt.
 
Like bimmertech said, an exhaust leak will get louder as the engine load is increased. It's not 100% dependent on engine speed either. So if you mash the throttle at 30mph in 5th gear, if it gets louder, it's probably an exhaust leak.

FWIW, they can "go away" once the motor warms up. As metal heats up, it expands, causing the gap between the leak to close.
 
It is also not unusual for the flange on some headers to warp slightly. I would at least try and put a machinist's edge across the flange. Or you can do like some and use the goober method (run 20 gaskets, etc to fill all voids. That is an exaggeration - some methods dont sound too bad to me, unless the material blows out).

Good luck.
 
CManT1914 said:
ROFLMAO :rlaugh: :lol: That reminds me of a saying

You only need two tools: WD-40 and Duct Tape. If it doesn't move and
should, use the WD-40. If it shouldn't move and does, use the duct tape.
Hey, I like that. :nice:

I think Macgyver's retawded little brother came up with that one. :D Then Mac used the leftover lubricant and duct tape to make a transmission and a bomb.
 
Get a metal rod, hollow perferably like some copper or anything and place it on your header, then put your ear to the other end, it will work like the ocliscope (what ever that thing the Dr. uses) and you should be able to find where the noise is comming from.

Also go for a drive, get it in 5th gear and very lightly give it some gas, you should be able to pinpoint if its comming from infront of you (header) or below you (H pipe).
 
91LX_5L said:
Get a metal rod, hollow perferably like some copper or anything and place it on your header, then put your ear to the other end, it will work like the stethoscope (what ever that thing the Dr. uses) and you should be able to find where the noise is comming from.

Also go for a drive, get it in 5th gear and very lightly give it some gas, you should be able to pinpoint if its comming from infront of you (header) or below you (H pipe).

Bold = fixed. If your doc uses an oscilliscope, it might be time to find a another doc (one uses an OS to measure the square wave of an appliance, solenoid, etc.). You can use one on a Fox IAC, for instance.
 
here is my plan of action. I am going to take w-d 40 and a socket set under the car, and tighen the exhaust. then if that doesn't work, find where the sound is coming from, and change gasket.

i am asuming the only gasket is between the head and the header flange.

oh and if you think you are guys think that you are going to get me place a piece of metal to my ear and listen to my car, your nuts. It might even work, but if my brother or parents came out side and seen me doing that they would make fun of me for a long time.
 
No, your brother would pat you on the back and be proud that you are using that method to track down the noise. I have a stethoscope that I use all the time for this kind of stuff. A wood-handled screwdriver works decently too, if you dont have metal pipe or a scope.

Good luck.
 
One other method to check for exhaust leaks, especially like you describe (loud on start up), is to simply put your hand close to the suspect area and feel for air puffs. That's how I tracked down a few leaks.

BTW, please do this only after the car has sat and cooled completely. Headers get very VERY hot.
 
HISSIN50, my brother would never pat me on the back, No matter what i did.
When i told him this morning that i have en exhuast leak, he told me "the simplest way to fix it is to do full exhuast from the header to the tail pipes." Sometimes i don't think he realizes that i don't own my own company, and don't have unlimed funds. what a re brothers for.