Warped Exhaust Flanges
 

Greetings

I have an exhaust leak on my truck, noticeable with the windows down at idle and very noticeable when accelerating next to a wall/curb/other car (annoying 'PSST' sound increases in frequency with RPMs). Can't hear it with the windows up, but I think that is the sound deadening mat doing its job. The joint between the headers and exhaust pipe looks like this

http://www.vetteworksonline.net/cata...1exhaust02.gif

with a gasket sandwiched between the two pipes and flanges. This doesn't seem like the best way to join two pipes (a ball-and-socket or welded flanges joined face-to-face make more sense to me), but that's what I've got to work with. The flanges on my exhaust seem to have warped, with a noticeable gap on the long sides between bolt holes. I've already replaced the gaskets once when the flange bolts came loose on the passenger exhaust pipe, but the noise is still there (quieter than before, but still annoying) and I think the warped flanges are to blame.

Is it worth my time to try and fix this leak, or will this type of joint always cause trouble? I could have an exhaust shop cut and install a new type of joint, but if I can avoid any unnecessary work that would be preferable. If I can fix it myself, how would I get new flanges on after cutting the old ones off?

Thanks in advance

Re: Warped Exhaust Flanges
 

Did you try the dead soft copper type gaskets or the cheapo composite ones there is a very big differance

Re: Warped Exhaust Flanges
 

I probably used the cheapo gasket. It definitely wasn't copper, more of a silverish gray thick material. I thought the thickness would help with sealing the gap between the flanges. Do you think a copper gasket would work even though the flanges aren't perfectly straight?

The silver ones were all I could find locally in a hurry

Re: Warped Exhaust Flanges
 

I found these 2-piece flanges as an option to replace the warped ones currently on the truck
http://www.summitracing.com/parts/wlk-36133/overview/
These would allow me to cut the old ones off, and put the new ones on without having to cut or remove any sections of existing pipe.

The only catch is the price. If I need to replace all 4 flanges (worst case scenario) at $24 each, I might just be better off paying a shop to weld a better type of joint on there. Am I wrong in thinking that?

Re: Warped Exhaust Flanges
 

You may not be wrong but you are going to spend more than you need to. I have the exact same header flage on my truck and they NEVER leak because I put the copper gaskets those flanges need to seal on when I built the truck.

13.97 for the pair from Summit Racing. PN is in the photo.

Re: Warped Exhaust Flanges
 

I see those are the dead soft copper gaskets cdowns mentioned. I'll give those a try, maybe they will save me from an uncomfortable afternoon crawling under the truck with an angle grinder!

Thanks for the help, fellas.

Re: Warped Exhaust Flanges
 

The link in post 1 shows a manifold type flange and people are pointing you to header gaskets. You may want to figure out what exhaust is on it before trying to solve the problem.
Stock exhaust uses donuts not gaskets where the manifold meets the pipe. https://www.google.com/?gws_rd=ssl#q=exhaust%20donut

Re: Warped Exhaust Flanges
 

Like this? http://www.vetteworksonline.net/cata...1exhaust03.gif

The end of my headers and the end of the exhaust pipe both have the flare and flange like you see in this picture.

Re: Warped Exhaust Flanges
 

What kind of headers do you have? Long tubes? Shorty? 3/4 length? brand? If the flanges are warped at the collector and the pipe... then no gasket will cure that leak unless the flanges are straightened back out.

The flanges you posted above are a stock manifold style with a dount gasket. Not my first choice in sealing anything.

Might just be time for new headers. By the time you pull those out and have a shop charge you "shop rates" for time, you'll probably be in it enough to buy a new set of headers.

Over tightening of fasteners is the #1 cause of leaking headers...

Gary

Re: Warped Exhaust Flanges
 

The truck has long tube headers, not sure of the brand because the previous owner put them on. I don't know much about exhaust, At first I thought it was just a cheap/quick fabrication technique, now I just think it's wrong.

Here is a sketch of what I'm talking about
http://i.imgur.com/unG9dso.jpg?1
I thought maybe there was some type of gasket that went inside the pipe flares, but I think this was supposed to be a ball-and-socket connector that was botched.

At the very least, I've learned a bit about exhaust pipes from all this :lol:

Re: Warped Exhaust Flanges
 

It's always fun cleaning up after a PO. Especially one who has the understanding of a gnat.

Re: Warped Exhaust Flanges
 

That's just a basic header collector flange and a basic exhaust pipe flange to bolt to a header collector. Been that way since the dawn of headers. A gasket just sandwiches in between the flanges held in place by holes that the collector bolts go through.

Gary