LS motors and broken exhaust bolts

John Kissel · 10-26-2013, 06:54 PM

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 · 10-26-2013, 07:37 PM

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 · 10-30-2013, 10:04 PM

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 · 10-31-2013, 02:24 AM

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 · 01-12-2014, 07:36 PM

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 · 01-13-2014, 10:38 PM

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 · 01-13-2014, 10:45 PM

Quote:

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 · 01-14-2014, 08:34 PM

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

10-26-2013, 06:54 PM	#1
John Kissel Member Join Date: Sep 2012 Location: Colt's Neck, n.j. Posts: 349 Likes: 766 Liked 230 Times in 94 Posts	LS motors and broken exhaust bolts 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

10-26-2013, 07:37 PM	#2
killintime6968 Member Join Date: Oct 2009 Location: Whitecourt,Alberta,Canada Posts: 236 Likes: 4,663 Liked 91 Times in 29 Posts	Re: LS motors and broken exhaust bolts 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.

10-30-2013, 10:04 PM	#3
Chipper Chapman Member Join Date: Jan 2004 Location: Belmont N.S. Canada Posts: 473 Likes: 246 Liked 166 Times in 71 Posts	Re: LS motors and broken exhaust bolts 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. __________________ Chris Chapman 1969 Chevelle NHRA F-G/SA 1090

10-31-2013, 02:24 AM	#4
John Kissel Member Join Date: Sep 2012 Location: Colt's Neck, n.j. Posts: 349 Likes: 766 Liked 230 Times in 94 Posts	Re: LS motors and broken exhaust bolts 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

01-12-2014, 07:36 PM	#5
John Kissel Member Join Date: Sep 2012 Location: Colt's Neck, n.j. Posts: 349 Likes: 766 Liked 230 Times in 94 Posts	Re: LS motors and broken exhaust bolts 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

01-13-2014, 10:38 PM	#6
CrateCamaro Member Join Date: Nov 2007 Location: Ontario Canada Posts: 411 Likes: 1 Liked 19 Times in 7 Posts	Re: LS motors and broken exhaust bolts 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. __________________ Tony Valerio 1968 Camaro 1700 IHRA H/CM 1701 NHRA SS/?A

01-14-2014, 08:34 PM	#8
John Kissel Member Join Date: Sep 2012 Location: Colt's Neck, n.j. Posts: 349 Likes: 766 Liked 230 Times in 94 Posts	Re: LS motors and broken exhaust bolts 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