Maddening exhaust leak between manifold & turbo!!

[King Salami]

About a year ago I found a leak between my exhaust manifold & turbine housing flanges while running MCCC through my engine. I've tried everything I can think of to fix it, but it's been kicking my ass! Sometimes it seals for awhile, but then it starts leaking again.
I've replaced the gasket 3 times (using both SS and metal-clad composite gaskets). I've taken the SS gaskets out twice to find them slighly "stretched" or elongated longitudinally. What caused this to happen? Overtightening?
I've checked the torque on the bolts to ensure that they haven't loosened (I'm using 2 Mitsu cupped washers on each bolt). I've had both the manifold & turbine housing faced by a machine shop. I've examined both parts very closely – there are no cracks; the leak is definitely where the parts mate up. The Evo III manifold is about 2 years old and the turbo is a brand new Evo III 16g GT. Both are perfectly port-matched. I also had the exact same leak with my old small 16g.
I just replaced all the manifold-to-turbo bolts & torqued them to specs, but this fargin' leak will not stay sealed for more than a couple days

What the f%*@ do I have to do to get an airtight seal between the manifold & turbine housing? Can anyone think of another type of gasket that I can use to get a good seal between my manifold/turbo? Has anyone else had a similar problem?

 

[FallouT]

I would think something like a copper gasket would work best. i cannt seem to find one, and i dont know if they are even made but i seems to me a softer metal would seal better than an ss gasket. just a idea. mabye you could get some high quality copper sheet and make your own gasket. although i dont know if it would stand up to the heat.

 

[nicknorth11]

the copper gasket is a good idea, I would definately check into the temperature it would be able to withstand and if it is high enough, go for that.

also, I had a pinhole leak at the same place and I fixed it by using spray-on copper gasket sealer. (It may actually be used instead of a gasket, I can't remember, but I got it at autozone and it works great). I am using a 3-layer metal gasket at that flange as well.

 

[98gst62]

Try a layer of high temp rtv. put it on both sides of the gasket, let it dry about half way and put it on and let it dry completely.

 

[King Salami]

Thanks for the replies.
I've tried using high temp silicone (Permatex Orange), but the high heat in this area just turns it to dust.
Nicknorth - where did you get the 3-layer gasket? I'm running a 4 or 5 layer copper gasket on my head-to-exhaust manifold & it seals like a champ after numerous removals/reassemblies. If I can just find a similar one for the manifold-to-turbo, I may get this thing whipped.

 

[nicknorth11]

I made it. It's pretty easy. Go to lowes or home-depot and buy a pack of ss roofing/flashing sheets. (I think they're actually for use around chimneys). They're about 4" x 6" and come in a pack of...30 or so. The pack only costs about 5 dollars. Then just cut out the design you need with some shears or a dremel. Hammer it smooth and you're done. Total cost is $5 and total time in cutting and prepping the gaskets is about an hour for 3. (It only took me about 1/2 hour, but i've made a few others).

Side note, you CAN buy these somewhere, I just don't know where.

I would highly recommend trying the spray-on copper gasket first. It works extremely well and worked for me in the same place.

Hope this helps.

 

[Module Unknown]

Did someone say copper? http://www.ffwdconnection.com/copper.shtml ...second gasket in the list. I found this because I need to order one soon to try and fix the same problem.

 

[JayRolla]

My brother had the same problem. He had the manifold and turbo housing surfaced to match just like you and no luck. The guy said the the metal on the evo parts where hard as hell to surface. Well after a year and no fix he decided to get a new mani becuase even surfaced it still didnt work. From working on the turbo so much the housing got a crack so we replaced the housing and mani. After that it works great. The evo mani was cast wrong somehow and would never could be surfaced perfectly. It was a bad OEM part.

 

[aero_sallee]

I've had extremely good luck using a thin layer of wheel bearing grease on the flange without gaskets. Have to stay off boost long enough for the grease to burn up and leave hard carbon.

 

[King Salami]

Thanks for the help, guys!
I think I'll give the copper gaskets a shot. Maybe I'll be extra anal & spray it w/ the copper gasket spray!

 

[Mr.Tao]

I had a similar problem like you. I didnt get a proper gasket and everything I tried was blown
and melted. So I ported the opening of my 14b turbo, mated it to the manifold with no gasket and under acceleration I couldnt feel any exhaust escaping.