Exhaust leak

[TAK65]

Hi all,
hope someone can shed some light here...
Mr Mechanic just replaced my cracked exhaust manifold with a good one. Everything was done by the book (shop manual). No leaks between manifolds and head but a bad one in the heat riser area, between intake and exhaust manifolds. The mating surfaces were checked and straight, new metal gasket used and bolts tightened (15 lb.ft as the book says). BUT one of the three bolts had to be loosened and re-tightened once as he/we forgot to reinstall the starter cable bracket under the bolt. Could this be the cause?
Further, is there any way to slide a new gasket (if needed) in between the manifolds without removing the whole assembly again? Any sealer recommended or is the metal gasket enough?

Thanks a million,
Tina

 

[fireman4]

You do not have to remove the entire assemble. I removed the manifold nuts and slid it away from the head, resting it on a 4x4 block of wood. It gave enough room to install a new gasket. I did a double gasket and used Copper Coat gasket sealer to marry the two together. You can use a magnet to remove and replace the hold downs. When replaceing hold downs back on the stud I used a long flat head screw driver to push them off the magnet. Not 100% leak free but it is 99% better and doesn't back fire very often. I will probably switch to headers when it gets worse again.

 

[TrailBeast]

Keep in mind that you can slot holes for bolts and studs to get a new gasket in if needed.

 

[KosmicKuda]

I have not personally used it but the /6 guys here say the Remflex brand gasket is the best one to use.
The thin metal one you have is difficult to seal.

 

[TAK65]

Thanks everyone, problem solved. The manifolds were not a "matched pair" so they required a little bit more tinkering with the torque sequence. Nice and quiet now.

 

[BillGrissom]

Slantsix.org probably has more opinions, but my method in the pre-internet days when we had to wing it, was to snug the nuts at the head, but not tight, then snug, the 3 crossover bolts, and keep repeating until all were at factory torque. Seems that would allow all surfaces to align. One time, I sat both manifolds faces on a perfectly flat optical table as I snugged in, though that only works if the head was similarly flat. I did occasionally get leaks at the cross-over and recall using 2 metal gaskets once.