Can we please clear this up. I have read many posts about which exhuast manifold gasket to use. I just purchased an exhaust manifold from thestreetsource.net and I am having exhuast manifold leak issues. I cleaned down the head where the exhaust manifold bolts up it is as smooth as can be, the exhaust manifold is clean as well.

First I tried the HAHN 3 layer metal gasket and it leaked like crazy from the passenger side of the manifold.

Next I tried the felpro gasket and it is still leaking from the passenger side of the manifold, not as bad as the HAHN but still bad.

Some suggest using a copper gasket with copper rtv silicone. The copper gasket can be re-used again and again. Some also say not to use the copper gasket and it leaks to much. The copper rtv silicone withstands temps up to 700 degrees. When I had my egt probe in the manifold it was reading 900 degrees at idle with a 14.7 air to fuel. I dont see how the copper rtv silicone would withstand this temperature.

My next step is going to get the stock manifold from the dealership, I read this is the best gasket to use, does anyone else agree??

use the copper rtv on the gasket. remember, your egt is reading the gasses in the manifold, not the temp of the gasket.

i have the copper rtv on my d/p gasket and manifold gasket.

Which gasket are you using and how long did you have to wait for it to setup??
Thanks,

I had the same problem, the maifold was warped and had to get surfaced. then used mls gasket from dodge. be sure to tighten it a couple of times after warming motor.

Yea the manifold is obviosley warped somewhat if it's leaked from the same spot with both gaskets.

Take it off. Take it to a machine shop.

Originally posted by Blizare
Yea the manifold is obviosley warped somewhat if it's leaked from the same spot with both gaskets. Take it off. Take it to a machine shop.

The head surface could be slightly off as well.

Exile Racing Technologies
http://www.exileracing.com
Go that way, really fast, if something gets in your way... turn.

I took it apart again today and bought the multi layer gasket from the dealership. I used rtv copper silicone on both the head side and the manifold side and bolted it all back together. Takes about 24 hours to fully cure. So i will let you know how it works out. It resists up to 700 degrees and I doubt it gets that hot in there. Also it is resists vibration and all mechanical fluids, good stuff just need to let it fully cure before driving the car.

Originally posted by Michael_97RS

Originally posted by Blizare Yea the manifold is obviosley warped somewhat if it's leaked from the same spot with both gaskets. Take it off. Take it to a machine shop.

The head surface could be slightly off as well. Exile Racing Technologies http://www.exileracing.com Go that way, really fast, if something gets in your way... turn.

Your totally right but probably not as likly and a maniold.

Originally posted by eclipse7782
I took it apart again today and bought the multi layer gasket from the dealership. I used rtv copper silicone on both the head side and the manifold side and bolted it all back together. Takes about 24 hours to fully cure. So i will let you know how it works out. It resists up to 700 degrees and I doubt it gets that hot in there. Also it is resists vibration and all mechanical fluids, good stuff just need to let it fully cure before driving the car.

I bet it still leaks. :P

Finally got it to seal up. I used the stock multi layer gasket from the dealership and I put copper rtv silicone on both the manifold and the head. Then i hand tightened each bolt. Next i did a half turn starting with the bottom 2 middle bolts, then the top 4, then the 2 outer bolts on the bottom. I kept doing this pattern until they were all tight. Then i let the car sit for 24 hours. The copper rtv silicone needs 24 hours to fully cure in 70 degree weather. No leaks at all. The silicone is 700 degree heat resistant, vibration resistant, and resists all mechanical fluids. Really great stuff just need to give it 24 hours to setup.

I have the same manifold. When I got to my house i test fitted it and it actually did not seal. The problem was the manifold flange did not clear the thermostat housing where it attaches to the head. I had to grind it down alot. This could be your problem. Hope the rvt works for ya but keep this inmind.

Only 700 degrees? That's not high enough, your exhaust will get hotter than that.


Brian

It will not get past 700 degrees do you know how hot that is?? At that temp the manifold would slide right off of the head.

Originally posted by eclipse7782
It will not get past 700 degrees do you know how hot that is?? At that temp the manifold would slide right off of the head.

Are you fucking kidding me :P

Your exhaust temps can get up to 1500 Degrees F. Thats over 800 degrees celsius.

Thank you sir. ^^

Yes, I know how hot 700 degrees is. I have an EGT gauge on my car. Even without boost, the exhaust is much hotter than 700 degrees. (I'm assuming you're talking 700ºF, not Celcius, since you've never mentioned it was C)

It's okay, you don't have to believe me.


Brian

Actually your egts are hotter w/o boost. OR atleast thats what Ive noticed.

Even w/o boost on the freeway you can reach the borderline limits.

I just said that to say that you don't need a turbo to get hotter than 700, even NA cars get exhaust temps higher than 700.

Thanks for the clarification.


Brian

It doesn't matter because the cylinder head to manifold mating surfaces are not going to get that hot.

No the EGT measures the gas temperature not the actual temperature inside the manifold. At idle my EGT gauge reads 850-900 when i had a leak I put my hand infront of the manifold and could feel the actual air leak coming out of the manifold if that was 900 degrees my skin would have melted right off the bone. Dark-red heat LAVA corresponds to 650ºC or 1200ºF. My EGT sometimes hits 1400 degrees you think it gets hotter then lava inside the manifold???

As for lava, it's actually about 1000 to 1200 degrees C depending on what source it has come from.

As for your header, I'll be curious to see if it works.

Brian

It does work I havent had a leak yet, the gasket is made for exhaust manifolds. It all depends on the lava, Dark-red heat LAVA is 1200 F
http://www.jegs.com/webapp/wcs/stores/servlet/CategoryDisplay?lang=-1&catalogId=10002&storeId=10001&categoryId=27111&searchItemId=129561&CT=999

Fair enough. I hope it continues to last for you. I apologize for the misinformation.

Good luck with the rest of your build,
Brian

I agree, hopefully it works but just wait till tomorroow morning when you fire her up. I got used to popping the hood, starting the dcar and running quick to check for leaks while the engine was still cool. :P

Goodluck!