[arkie 2]

I've had an exhaust leak for awhile and decided I would finally get around to putting new header gaskets in. The old gasket I pulled showed definite signs of a big leak right where I thought it was. However, when I put the new gasket in (Mr. Gasket Ultra Seal) there is a new leak in a different location (bolt hole #1). These new gaskets don't look like the old ones (the #1 and #8 bolt holes on the new one are open ended) and I had a devil of a time trying to bolt it up on the first try. I took it out and overlayed the old gasket and noticed they didn't align perfectly. If I centered the 6 middle bolt holes the end holes on the new gasket were slightly off center and that's where the new leak is. Any suggestions? Different gasket? Gasket surgery? Any help is appreciated.

[.boB]

Differant gasket. And then use some silicone sealant.

[arkie 2]

Originally Posted by .boB

Differant gasket. And then use some silicone sealant.

I went out and pulled the new gasket off. Looks like it has sealant already applied as I wasn't able to get it off without tearing it because it was already sticking even though I'd only run the engine about 5 min. Put the remaining gasket from the package back on and it sounds even worse if that's possible. I'm not too keen on cranking harder on the bolts, doesn't seem to do any good anyway. Frustrating as heck when I thought this was going to be a straight forward fix.

[.boB]

If the gasket doesn't fit right, it will always leak.

Dry gaskets will stick pretty good after a while. Use the red high temp silicone gasket sealer. Be sure and let it cure well before starting. I know quite a few people who don't use gaskets, just the silicone. I'm not that bold.

[v8only]

I've never once in my life ever used silicone for a header gasket. If it leaks right after install, investigate the problem, don't cover it up.

pull the header and check the flange with a flat edge. your header flange is likely warped...straighten them, which may not be possible, or buy new headers.

[.boB]

Originally Posted by v8only

I've never once in my life ever used silicone for a header gasket. .

You should try it sometime; you don't know what you're missing. I use it on my street/track car, and it holds up well during two track seasons.

The truth is, headers can be tough to seal. Especially cheap ones. All that expanding and contracting causes a lot of distortion. If everything isn't perfect, they can leak. Especially if you regularly race the car. Silicone sealant can give you the extra edge you need. That's why so many professional race teams use it.

[v8only]

I believe it.

If I have a problem come up, I'll give it a wack. The stage 8 locking header bolts work real real well though, once you've got it all locked in initially without leaks.

[arkie 2]

I'm resurrecting my old thread just so I can relate what fixed the problem in case anyone else has this problem and runs across this thread with a search. I got a good strong light so I could see the face of the header and saw some gasket material stuck to it. Since I had less than an inch of clearance between the header and the motor after I unbolted the header I couldn't get anything in there to clean it off. I went down to the hardware store and spent 30 minutes looking at everything that I thought might help.

I wound up with a flooring knife of all things because it had a long curved blade and with a sharp tip. The curve of the blade allowed me to manipulate it unlike a straight one. Once I got it into position I was able to manipulate the tip and chip away at the gasket material. It took awhile but it worked. I also put copper gaskets in this time. The only noise I hear now is what's supposed to be there! I'm not sure what cured the exhaust leak, cleaning off the header face or putting in the copper gasket but either way it's fixed. No silicone sealant required