Overpipe gasket exhaust leak

[THEWAKLER]

Guys need some help on the exhaust leak issue.

Backstory: Installed JDL UEL headers, used gaskets supplied with headers. Everything was tight and sealed well after install.

2wks Later: Noticed weird noise under load, did my best to capture it in the video below. Ended up being the gasket on the header/overpipe had been deteriorated in a .75" section, where the material had corroded/been overheated/destroyed. All bolts were properly torqued.

Area where leak was/is:




https://www.flickr.com/photos/jwalk7...posted-public/

9 wks Later/1wk Ago: Noticed the same noise, in the same locatoin. Ordering a new gasket tonight to switch out, but trying to identify the root cause? Any thoughts? I am lowered 1.2" all around, and the back muffler occassionally scrapes the speed bump in my neighborhood (maybe putting extra stress/leverage on the gasket?). Talked to some guys at work today, and they said it might have been caused by excess stress on the muffler, and that a flex joint on the overpipe/midpipe might be able to reduce some of that strain, thus preventing stress on the gasket. Any help would be greatly appreciated!

[humfrz]

I suggest you take the bolts out between the header and over pipe and remove what's left of the gasket. Try to mate the flange of the header to the flange of the over pipe. In a relatively relaxed mode, check the gap between the two.

If it is quite large or not "straight" make a gasket out of the appropriate material to fill the void. If it's a big or really lopsided space, the "material" may have to be a custom made metal spacer.


humfrz

Back in the day, if two exhaust pieces didn't quite come together, we would wrap a big ol pipe wrench around one pipe then heat the pipe to cherry red with a blow torch and crank on the pipe till it "fit".

If that didn't work, we would say screw it and stick a piece of "flex pipe" in there .....

[DocWalt]

You can use a Remflex gasket. I kept having issues with gaskets at that flange too.

[Figo]

Originally Posted by THEWAKLER

9 wks Later/1wk Ago: Noticed the same noise, in the same locatoin. Ordering a new gasket tonight to switch out, but trying to identify the root cause? Any thoughts? I am lowered 1.2" all around, and the back muffler occassionally scrapes the speed bump in my neighborhood (maybe putting extra stress/leverage on the gasket?). Talked to some guys at work today, and they said it might have been caused by excess stress on the muffler, and that a flex joint on the overpipe/midpipe might be able to reduce some of that strain, thus preventing stress on the gasket. Any help would be greatly appreciated!

Have you solved the problem?
I have the same issue. And it happened twice.

[Figo]

Originally Posted by DocWalt

You can use a Remflex gasket. I kept having issues with gaskets at that flange too.

Have you solved the issue with Remflex gasket?

[DocWalt]

As I posted above the fix for me was to use a Remflex gasket. I sent the following info to OP, but I've got no idea if it fixed his issues.

I used a Remflex 6005 gasket. Needed some finagling with the holessince the bolt spacing isn't perfect, but it worked well. No more leaks

I've had Remflex gaskets on my exhaust for a year now. I recently had to pull the header for unrelated work and the gaskets showed no signs of leaking. I did have to replace them though as they pretty much bonded themselves to the flanges.

[kch]

Originally Posted by DocWalt

As I posted above the fix for me was to use a Remflex gasket. I sent the following info to OP, but I've got no idea if it fixed his issues.


I've had Remflex gaskets on my exhaust for a year now. I recently had to pull the header for unrelated work and the gaskets showed no signs of leaking. I did have to replace them though as they pretty much bonded themselves to the flanges.

I had problems with the remflex bolt spacing. The bolt holes were way too close to the tubing and i couldn't install properly. I tried to expand the bolt holes but it didn't work.

[DocWalt]

Originally Posted by kch

I had problems with the remflex bolt spacing. The bolt holes were way too close to the tubing and i couldn't install properly. I tried to expand the bolt holes but it didn't work.

There's two remflex gaskets that work. The 6005 has a slotted side and a side with a hole. There's another Remflex gasket 8026 that I used when installing my Perrin CBE which fit perfectly there, but IIRC the hole spacing wasn't all that nice for the header/overpipe flanges.

I used a dremel with a sanding wheel to oblong the holes out the first time. Kind of a pain, but it worked. The second time I used a utility knife and just cut the holes out to the edge of the gasket so it just had two slots which worked a lot better. Obviously you have to be careful to not ruin the gasket, but it was less time consuming.

Either gasket works, and they both require some customization, but it's worth it to not have to deal with leaks. Mine are fine even after a couple of track days and a lot of daily driving. The other gaskets would have been blown out by now.

[Figo]

Originally Posted by DocWalt

There's two remflex gaskets that work. The 6005 has a slotted side and a side with a hole. There's another Remflex gasket 8026 that I used when installing my Perrin CBE which fit perfectly there, but IIRC the hole spacing wasn't all that nice for the header/overpipe flanges.

I used a dremel with a sanding wheel to oblong the holes out the first time. Kind of a pain, but it worked. The second time I used a utility knife and just cut the holes out to the edge of the gasket so it just had two slots which worked a lot better. Obviously you have to be careful to not ruin the gasket, but it was less time consuming.

Either gasket works, and they both require some customization, but it's worth it to not have to deal with leaks. Mine are fine even after a couple of track days and a lot of daily driving. The other gaskets would have been blown out by now.

So you will recommend 6005 over 8026 right?

Also we have the same gasket between Header&2.5 overpipe, between 2.5 overpipe&2.5 frontpipe, and between 2.5 frontpipe & aftermarkt Catback right?

[steve99]

Try the grimmspeed gaskets

you can get double thickness ones
http://www.grimmspeed.com/grimmspeed...st-gasket-set/

also put some high temp anti-seize on the nuts/bolts and make sure they turn freely so they torque up correctly. Rusty dry bolts will often work loose when heated as most of the "torque" was "used" up overcoming the friction.

[DocWalt]

Originally Posted by Figo

So you will recommend 6005 over 8026 right?

Also we have the same gasket between Header&2.5 overpipe, between 2.5 overpipe&2.5 frontpipe, and between 2.5 frontpipe & aftermarkt Catback right?

I preferred the 6005, but they both require some customization. IIRC the 8026 fit perfectly on my Perrin CBE, which was nice.

Originally Posted by steve99

Try the grimmspeed gaskets

you can get double thickness ones
http://www.grimmspeed.com/grimmspeed...st-gasket-set/

also put some high temp anti-seize on the nuts/bolts and make sure they turn freely so they torque up correctly. Rusty dry bolts will often work loose when heated as most of the "torque" was "used" up overcoming the friction.

I tried the Grimmspeed gaskets... Getting them to seal was a bit of a crapshoot. They don't have a compressible fire ring like stock so it's just metal on metal.

I definitely agree on the anti-seize. Just be careful if you're using it on the Remflex gaskets, don't over-torque because you can over-crush them.

[TruRace]

I also had quite a bit of trouble getting the Grimmspeed gaskets to seal. I eventually gave up and grabbed some permatex ultra copper, no leaks so far. Messy but works.

[Trust86]

Originally Posted by TruRace

I also had quite a bit of trouble getting the Grimmspeed gaskets to seal. I eventually gave up and grabbed some permatex ultra copper, no leaks so far. Messy but works.

^^^This guy knows his shit!
grab a new gasket and throw some high temp rtv on both sides and be done with it forever. Did this to all my exhaust gaskets from downpipe back on my S15 when I was in Japan.

[Fakk]

Was the sound as if something metal was loose and tinkled back and forth under more than idle load? I think mine makes the same noise on startup and any load. If so, I guess I found my problem.

Right now I have Grimmspeed header gaskets, this "Subaru OEM 2.5" gasket from speedfactory between headers and overpipe, and a thicker gasket the rest of the way back. I took it to an exhaust shop, and they said I don't have any leaks.