Trouble with Exhaust Manifold to Pipe Seal?

[kevinmrowland]

Does any one else have trouble with sealing where the flanged exhaust pipe bolts to the bottom of the exhaust manifold?

I have never been able to get it to seal real well, putting two doughnuts in there makes it alright but not great.

Replaced the manifold gasket & while it was out I checked that the seat was flat, seemed ok.

I thought that maybe the rest of the exhaust was not letting the flange sit flat so I cut it off to just deal with the down pipe.

The flange on the pipe was bent where the main bolt pressure is, so I heated it up and bent the wings back.

Made an aluminum spacer to sit on the flange to hopefully shove the doughnut tighter into the manifold, that did not work at all.

After all that I put it back together with 2 doughnuts and it leaks just about as much as when I started this whole thing a few hours ago.

I figure I would ask if anybody had any great tricks before I went and welded the exhaust back together.

Thanks, I'm off to search now.
Kevin R.

 

[Gurr]

hmmm, did you ever find a solution kevin?
my last doughnut only lasted a couple thousand miles and I'm going to see how long a new one will last...I just don't want to be putting in a new one every oil change.

 

[Spook50]

This is on a 3FE right?

It's possible the flanges on either the manifold or the downpipes are just slightly warped enough to not allow for a good seal. I haven't had that problem yet, but if it gets to that point I'll get a junkyard manifold (or just say screw it and order a header) and have ball & socket type flanges welded on. A pair of these in a 2" variety for each downpipe coming off a manifold or header would be perfect: Flowmaster 15938 Flowmaster Header Collector Ball & Socket Flange Kit

Zoinks I just realized how old your original post is. Well hopefully the link will help someone out

 

[csd4682]

I discovered that the po of my truck must have had a similar problem. When I took off the down pipe there was a donut gasket that was larger than the oem gasket, and a crush gasket shoved into the pipe. The truck is not running right now, but I was able to find the same parts he used. I ran the truck for about 2 miles when I bought it, and it didnt seem to leak from there, so hopefully his combo was right. I will let you know. I am joping to have it running in a couple of weeks