exhaust manifold leak

[mjboehm]

i just put a new turbo on my car b/c my other turbo took a crap. i hooked up everthing and i have an exhuast leak coming out of the manifold next to the head. i first had an exhaust leak out of the o2 housing fixed new gasket same as the turbo and bottom of the turbo manidfold. now it is leaking out of the passenger side of the manifold. it makes my car running like crap and when i give it gas it stumbles. when i changed my turbo didn't take off manifold.i just loosen a couple of bolts on that side and i made sure they were tight. so now when i start my car i have and exhaust coming out of #4 exhaust port where the head and manifold connect. i noticed the gasket has oil on it. i know it was from when the old turbo went out. also the gasket is metal. any info would be great on how to fix this without taking it off the car. unless i have to take it off the car and seal it with ultra-copper gasket maker.

 

[TSiAWD666]

Have you tried to replace the gasket, or tighten the nuts for the manifold/head? Not trying to be a smart ass but I read you see a leak, but not that you made any attempt to fix it.

The metal gasket can fail there. Oil might be from your valve cover gasket rather than inside the head. If when tightening the nuts they won't torque to spec and just keep spinning, you've stripped the threads in the head and will need to heli-coil. The nuts could just be loose, perhaps from being removed previously as they are crimped nuts (at least stock) and can weaken from repeat use and simply come loose.

Oh, make sure to tighten the nuts on the manifold/head slowly and evenly, so as to help make sure everything gets torqued to the right spec but also to minimize chances you pull the studs out of the head's threads (heli-coiling these is not fun). You'll find yourself tightening one side which allows more tightening elsewhere. Also re-tighten after getting the system warmed up after a run that heats the section as everything will loosen just slightly (from the heat of course).

I forget the torque spec on these... 13 ft.lbs.?

 

[mjboehm]

tried to re-tighten the the nuts/bolts on the head there tight. they are not stripped so i will start with replacing the metal gasket on the manifold/head. thanks for the info

 

[TSiAWD666]

I've never experienced this but in the past I've had others warn that a prolonged leak can warp the head surface where the manifold meets making it very hard or impossible to get a seal there. The fix for this would to have the surface machined flat, but as you can imagine that is a lot of work requiring removal of the head from the car.

Try replaceing the gasket first Make sure to clean the area as best you can prior to installing the new gasket as you probably will have carbon build-up around the ports.

 

[mjboehm]

I just put a new motor in my car about 150 miles ago didn't leak. then my turbo took a crap and got oil through out my motor and exhaust/ic piping.thats what i was wondering since there is oil on the gasket it is not sealing correctly because when my o2 housing was leaking i took the gasket off and got a new one and the case between turbo and manifold i have a thick metal gasket so i cleaned it off and put a thin laer of ultr high temp copper rtv on it. it stopped the leak there and now it is started at cylinder #4 so i was going to do the same thing there when i get a new gasket. thank for the info

 

[1bad92awd]

I would replace the gasket. Even though you never actually took the gasket off, you loosened it plus you mentioned that it had some oil on it. I would start there, and see if that fixes the problem. I've never actually loosened the manifold, i've only taken it off and replaced the gasket.

 

[dsm-onster]

If you suspect your gasket surfaces are not flat, try running a composite-like n/t gasket to see if that cures the leak. . . Either way, a gasket replacement is in order. . .