Finding an exhaust leak?? (1 Viewer)

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I have tried several times to locate an exhaust leak in my 350 TBI FJ55. I have a nice scar on my left hand from feeling around the exhaust manifold looking for that leak. It is not noticable at idle, but is quite loud when accelrating. I am using 1981 corvette stock headers that do not use any type of fiber gasket with the exhaust pipe. I don't think the leak is there.
Below is pic of one of the manifolds.
Anyone have a 'trick' to finding the leak?
out of the pig.jpg
 
If it's not at the manifold, wait for a cold morning when you can see the exhaust. Should be able to see a vapor trail from where it's leaking.
 
I use a stethescope with tubing connected to one earpiece and then tied or taped along the rod for rigidity. You run it all around the joints and listen for air passing over the tip. You have to isolate it from fan air.

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have you tried partially blocking the exhaust pipe (a soft soled shoe pressed onto the pipe by someone sitting on the ground will work) and listening? This should make the leak more noticable.
 
Maybe a length of garden hose? One end to your ear, poke the other end in and listen/feel for the leak?
 
I found an exaust leak using a spray bottle with soapy water in it. Bubbles indicate a leak.
This reminds me of that Far Side cartoon with the cave men holding meat over the fire with their bare hands. They look like they are in a lot of pain. Another cave man is holding his meat on a stick over another fire and one of the cave men says, "Oohh, look what Zog do!"
 
As mentioned (kinda) ... zip tie a couple socks over (NOT IN) the tail pipe to give a little more back pressure and this may help with your quest.
 
This may sound stupid, but it worked for me. I put a couple of smoke bombs in the tailpipe of my truck (white works pretty good). roll them in there at least a foot or so. When they start smoking really good ,blow the smoke into the exhaust with shop air or by mouth(dont burn your lips). Plug the tailpipe with a rag and turn over the engine with the starter. Don't let it fire off. (disconnect the coil wire) It will give enough perssure in the exhaust to force out the smoke wherever there is a leak. It really does work! You can do it over and over until you find the leak. You can also back pressurize the system with the shop air and find the leak that way, the only thing is that it will find open exhaust valves that way.
 
I have used a piece of fuel hose with one end stuck in my ear for finding exhaust leaks. Seemed to work pretty good on my 2F.
 
Colorado Boy-74-FJ40 said:
When they start smoking really good ,blow the smoke into the exhaust by mouth(dont burn your lips).

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Useless without pics
 
This is not good :), better safe then sorry.
 
disconect your fan and run sea-foam through your intake... or any other carbon remover. should be @~2000rpm. you WILL see smoke at any leak.
HTH, carl
 

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