Exhaust Manifold replacement

[performance1985]

Since I just found out about the overwhelming problem GM has with the exhaust manifold bolts shearing off in the heads, I now need to replace my manifolds. My 06 has only 59k miles on it, and three bolts sheared off - #1, #7, & #8.

It's amazing that GM knows about this huge problem and won't do anything to help fix it - except take our $1100 to repair it. They acted like it was the first time they heard of the problem.

Off my soap box for my questions: the bolts connecting the downtubes to the manifolds, do they need to be heated up to break the nuts loose? Someone in another forum mention that GM uses a yellow threadlocker on the rear brakes - which needs to be heated to break-free.

Also, anyone pulled out sheared bolts from # 7 & # *8, with the heads still on the motor; or, do they need to be removed - due to space.

I ordered Doug Thorley Shorty's to replace, and no way I'm paying the dealer to fix.:flame:

 

[0352Marine]

Since I just found out about the overwhelming problem GM has with the exhaust manifold bolts shearing off in the heads, I now need to replace my manifolds. My 06 has only 59k miles on it, and three bolts sheared off - #1, #7, & #8.

It's amazing that GM knows about this huge problem and won't do anything to help fix it - except take our $1100 to repair it. They acted like it was the first time they heard of the problem.

Off my soap box for my questions: the bolts connecting the downtubes to the manifolds, do they need to be heated up to break the nuts loose? Someone in another forum mention that GM uses a yellow threadlocker on the rear brakes - which needs to be heated to break-free.

Also, anyone pulled out sheared bolts from # 7 & # *8, with the heads still on the motor; or, do they need to be removed - due to space.

I ordered Doug Thorley Shorty's to replace, and no way I'm paying the dealer to fix.:flame:

Yes, that is how I removed mine. My cats were about 65% clogged at 100,000 miles and I could not figure out why I was losing power until I pulled the cats out. I tried everything to remove those nuts on the manifold to no avail. Finally I decided to heat up the nut I got it to a dark red then put the socket on it and it came right off. I would not get it bright red hot as it might weld itself to the bolt. Hope this helps

 

[performance1985]

I got lucky on the bolts by #7 & # 8 - if you want to call it luck. I was able to get a pair of small channel locks on the bolts and work them out. Of course, I had to remove the fire-wall metal and a bunch of other crap.

The bolt above # 1, not so lucky - it was sheared. I tried the method I read about on here: starting with a small left-hand bit I drilled down into it, before trying to use the easy-outs to back it out.

Now I'm screwed. The bolt jacket is not coming out.

Anyone have suggestions/help, before I end up having to pull the heads and taking them to a shop?

 

[87gtNOS]

updates?

 

[performance1985]

Yeh I got tired of trying to make sure the front driver's side bolt was all out. I pulled the heads and took it to a shop for a valve job. They ended up Heil-coiling the front bolt.

Everything has been bolted back up and changed over to Doug Thorley Headers - heavier bolts now.

Should be good to go for a while. I wil be posting more updates soon.