LS motors and broken exhaust bolts

[John Kissel]

We have a '06 TrailBlazer SS that is pretty quick when it and it's electronics are in the mood. Last night I was changing plugs and noticed the rear exhaust manifold bolts on both banks don't have the heads on them anymore. I found one bolt head between the heat shield and bottom flange, and it looks like it popped off the shank at the last thread. Anybody else come across this problem, since there are 3 metals involved and they all expand and contract at different rates. Thanks, John Kissel

[killintime6968]

Very common on LS engines in pickups. Most times u can pull the manifolds and get remaining bolt out. Sometimes u end up having to pull the head.

[Chipper Chapman]

Very common, I've never had to pull a head, but i charge by the hour so patience is a virtue. I use a soft (cheap parts store) m8 bolt to replace them, they seem to move with everything better and not break.

[John Kissel]

Thanks for the info. and suggestions. Asof right now all is quiet, and my hands have healed from changing plugs and wires. This poor truck has had to deal with the liquid salt that is used around here, and I can just imagine what more problems I could get into. Aero Kroil works miracles, just don't want to get greedy. John Kissel K242

[John Kissel]

I got a bulletin from Dorman yesterday about some new stuff they offer. Anybody use #917-107 exhaust manifold repair kit yet. It's a bracket that bolts to the back of the head and also pushes on the manifold where the broken bolt is. Thanks, John Kissel

[CrateCamaro]

Just did this job on my personal vehicle and used the new dorman manifold bolts. Some of the studs were still in tact with some shoulder sticking out of the head so they were easy enough to get out....but of course there were a few broke flush with the head....the bolt closest to the firewall on the drivers side. Get a handful of 1/2 inch and bigger nuts, clean the zinc plating off them with the grinder and fire the welder up set on kill. 3 attempts and it came right out. Not a great job to do, much easier with the plastic inner fenders out.

[CrateCamaro]

Originally Posted by John Kissel

I got a bulletin from Dorman yesterday about some new stuff they offer. Anybody use #917-107 exhaust manifold repair kit yet. It's a bracket that bolts to the back of the head and also pushes on the manifold where the broken bolt is. Thanks, John Kissel

Bolting that repair kit onto the back of the head is 10x harder then dropping the manifold. good penetrating fluid and a little heat they will fall off. I bought new manifold studs, doughnuts, manifold gaskets (usless because gm used an MLS style gasket that's re useable) and bolts. Made the job real easy. Im in the rust belt as well so I know what you mean when you say liquid salt. Much easier job in the summer, nothing worse then a car dripping on you when your trying to work.

[John Kissel]

Gee, Thanks. Of course these clamps are made in chikneeze, hope they get 1 1/2 cup of rice a day instead of just 1, so maybe they will fit. Just from how my luck goes, I'll try these as I'll only make my hands bleed a little compared to taking more of this rusty stuff off. Thanks, John Kissel