well, my manifold had one of the 4 DP studs broken off in it. I tightened the other 3 don as tight as possible without doing damage and added a hi-temp silicone as well. I am still getting a stinky leak...without removing the DP, turbos to replace the manifold, is there a good sealant I can use around the flange of the DP to seal it up?

Trev

 

dont just patch it up..
do it right and remove the offending stud..

 

No sealant will hold up in that location. Only the stock metal gasket can take those temps. You need to extract the broken stud.

Dave

 

I suppose I will have to drill it out since it is recessed into the manifold. I need to probably just replace the manifold. I know this will be a PITA.

Trev

 

+1 on getting the proper metal gasket.

Lastly, don't OVERTIGHTEN the nuts or the studs, tigthen them to spec. only, as the gasket needs some "room" to thermally expand & contract.

Use a torque wrench, and high-temp anti-seize which will decrease the torque spec. about 15%.

If you decide NOT to replace the manifold and extract the stud (either on the car, or on a bench), you may want to try this:

Purchase some Aero Kroil (Kanolabs.com) and liberally soak the stud for 12-hrs.
Strike the stud with about 2-3 firm blows with a punch, and soak for another 12-hrs.

Purchase an appropriate-sized LEFT-HAND drill-bit, and use a center-punch so the drill doesn't skip. I would start with a smaller left-hand drill-bit to start a pilot-hole.

I believe the stud is made of Inconel which is very hard as well as being very heat resistant.

Regardless, use some cutting-oil to keep the drill-bits from overheating which will keep the bit from loosing it's edge.

Hopefully the left-hand drill-bit will catch-enough and screw-out the stud.

If not, hopefully you will get the stud down to a very thin hollow stud, which can be bent down (or very gently cut with a Dremel carbide-bit into two half-moons) and then extracted.

As a LAST RESORT I would try a stud-extractor. The reason:

In the majority of cases, stud-extractors, especially small stud-extractors BREAK leaving the tip of the extractor in the stud!

This material is SO HARD it is a major PITA if not impossible to remove without either special equipment and/or damage.

If you get this far (a broken stud-extractor), then I would definitely just replace the manifold (still use high-temp anti-seize and torqued to spec).

Heck, knowing that extracting is a major PITA, esp without the part removed and on a bench, you're probably better off just replacing the manifold just like you said.

Best of luck.

:-) neil

 

Thanks for the tip. If I can't retract it, I will have to get the turbo manifold from someone else. Have a great day!