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Ive been driving my 67 camaro around and it has sounded just fine until recently. Today it was driving fine and then I started to hear a constant exhaust sound, similar to the sound an early 1900's roadster would make. It does not sound that nice and I am worried the exhaust system may be damaged in some way. It sounds like it is coming from the left side (when looking at engine) exhaust manifold area. Any suggestions as to what could be the problem?

Thanks, Samuel
 

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Provided your car has a stock exhaust. Chances are it's a gasket located at the heat riser. There are two gaskets here, a round (i call it a donut gasket) and a flat triangular gasket. It could also be the heat riser itself or rusted broken studs. Over the years they rust out and cause leaks. The worst case (most expensive) scenario would be a cracked manifold. A muffler shop should be able to fix you up unless it's a manifold. If so you can still find them at the Camaro parts suppliers.
Hope this helps
Jim
 

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Thanks for the input. My guess is that the sound is due to an exhaust leak coming from where the manifold meets the pipe. I took a closer look at the exhaust manifold and it looks a little odd. There is a little lever and spring mechanism where the exhaust manifold meets the pipe (does anyone know what that does?). I flipped the lever back and forth but it did not change the sound. It also leaks like there could be a broken gasket. Any suggestions?
 

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A tip.

If you are careful you won't break a stud or two or three........ He, He!! You will love it if you do. NOT!!!!! Gotta drill the sucker(s) out and hopefully use an easy-out to finish the job.

I have had to drill them out and use a thread remover offset, pointed, half round tipped chisel. I don't know the name of the chisel unless it is just a keyway cutter??? And also a tap... A real pain to say the least..

Then use brass nuts as replacement nuts on new studs. They hold up to me better then the steel ones if they aren't already brass??

pdq67
 

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the lever on the passenger side exhaust manifold is the heat riser. when the engine is cold it has a spring that closes the flapper inside the pipe. this diverts warm exhaust air up and over the engine under the carb. to warm it. there is a path inside the heads and intake manifold for this. when the engine warms up this spring relaxes and lets the exhaust exit through the pipe. sometimes these flaps get stuck shut and really rob the horsepower. sounds like yours is moving but check to make sure it springs back when cold.

exhaust noise sounds like a donut is shot between the pipe and manifold or heat riser. several extensions and a deep wall socket from underneath the car might be easier then from on top reaching down. warm the car up and turn it off and shoot lots of wd-40 on the bolts. work them loose by going back and forth don't try to take it straight off. break it loose and soak it some more with the wd-40 or liquid wrench. give it time to work.
 

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There will be a heavy composite "donut" between the flange on the pipe and the bottom of the heat riser valve, which is probably the source of your leak. Most likely it's missing the internal stepped sleeve which fits in the flanged end of the pipe that reinforces the inside diameter of the "donut"; Bubba likes to leave them out, so the "donut" collapses and disintegrates.
 

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And years ago as I bet John will agree to is that stock exhaust pipes were sometimes shaped like the end of a brakeline, except the flange is made so that it is down a ways from the pipe end and then the pipe sticks back up to form an integral 1/2" or so pipe like John mentioned that Bubba liked to leave out so somebody in the repair business would have to redo it by having to install another donut again in all not that long a time...

You know, make work sorta sh-t!!!!

Seen it done and never went back to that shop except it was on the wife's '77 AMC Matador straight six motor's exhaust years ago!!!!

I ended up making a special trip to St. Louis and buying a half dozen of the AMC stock steel donuts b/c the POS composite aftermarket Chevy type ones wouldn't hold for very long at all...

pdq67
 
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