Sounds like a old tractor

[JD 1931]

Suddenly the A developed a loud exhaust noise coming from the manifold area so I order a new muffler pipe connector and copper seal (fell apart , discarded it) for the manifold connection to pipe and installed them along with gasket sealer in tube and made a tight fit, improved the flange on the pipe also. Started it up and same noise, it might be from the exhaust manifold or the head gasket, replaced intake and exhaust manifold about a year ago using the better copper gaskets and the manifolds were planed, worked well. Next is to remove manifolds and inspect. Any suggestion? Thanks, J.D.

[Joe K]

If done properly the connection between the manifold and the exhaust pipe is best done MINUS any gasket. BUT - one needs to assure that the manifold "mating surface" is a true cone shape, sealing surface is all there (rust can erode the surface) and the pipe "aligns" to the cone.

Likewise, one has to examine the exhaust pipe flare and make sure the flare matches the manifold cone and meets it all the way around. A ball pein hammer and a piece of steel plate can be used to increase/decrease/modify the flare. (many muffler shops will re-make the flare at minimal cost.) The exhaust pipe bend itself can be modified to bring the heroic sized "flare compression fitting" (what it truly is) together in a match BEFORE adding the clamp.

AND - to add insult to injury, many aftermarket clamps are not properly shaped to bring the two pieces together. If you have more than one clamp available, try them out and see which one offers the best fit. Of my clamps, the "largest" seemed to be the clamp of choice and is probably an original clamp. Other two or three clamps were smaller and less effective and probably aftermarket replacements.

I hope the modern crop of clamp re-pops are more accurately made.

It is possible to put a ring of pipe dope on the mating cone surface and then clamp everything together: the pipe dope until it bakes out acts as a sort of "lubricant" to allow the mating pieces to find their "best spot." Once baked out by the hot exhaust, the pipe dope will prevent a leak from developing as everything "bakes together."

Hope this helps,
Joe K

[chrs1961815]

Like Joe said, don't use the gasket. They cause more problems than good. Also, I don't like the repro clamps. There have been problems with the fit of them in the past, so why buy them when there are plenty of good originals around? Also, like Joe said, make sure everything is the right shape (muffler and exhaust manifold). And a little muffler sealant would not hurt. If you use just enough it will not even be noticeable.

[chap52]

If after removing that gasket as suggested you still have the same noise I would consider the exhaust manifold gasket. If the noise you are hearing includes a tapping sound that increases with rpm's I would feel almost certain it was that ex. manifold gasket.
Been there...Chap

[JD 1931]

Thank you for the replies. I did not use the gasket because it fell apart and was discarded . I did get a good seal on the clamp on manifold but still got the noise and was asking if exhaust manifold or head gasket could be the problem?


thanks, J.D.

[Joe K]

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It may in fact be the manifold itself. My own similar experience (the one where I discovered the differences between clamps and discarded any gasket on the flare joint) ended by discovering minute "cracks" in the manifold itself. I found these by pouring a cup of 30W oil onto the manifold with the engine operating and watching the bubbles form and the oil vapor being thrown by gas-pressure from within.

A new manifold fixed the problem.

The problem with the busted manifold then became one of "its not heavy enough to be a doorstop." Much simpler to remedy.

Joe K

[JD 1931]

Just took off manifolds and found blown gasket on #2 exhaust. time to call Mikes...Thanks, J.D.

[JD 1931]

Is 30 lbs torque enough for the manifold nuts? J.D.

[ryanheacox]

I believe spec is 25-30 lb-ft