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New Avalanche owner Help - Missing Exhaust Manifold BOLT

Prado

New Member
Joined
Jul 17, 2021
Messages
6
Hi, I just bought a an Avalanche 2007 ltz. At the moment I need to bring it up to condition. Turns out I have a leak in the manifold due to missing bolt, maybe. Sounds like a hemi truck. I'm thinking not paying the try and just change the exhaust system completely as changing gaskets and fixing bolt issue will 500$.. any ideas whether I should just invest in the new exhaust system or just trial and error fix ?
 
I had a single exhaust manifold bolt broken on each side of the engine in my EXT.

I had my mechanic replace all of the old bolts and install new exhaust manifold gaskets on each side.

I'm glad I had the shop handle this repair since even to get the already broken bolts extracted, they had to remove both exhaust manifolds and all of the remaining bolts.

Several more of the remaining old bolts broke upon removal and had to be extracted, as well.

Since I am not able to weld anything at home, I would have been in a pickle if I had tried to handle this repair on my own.

And that $500 you mentioned would have been a bargain in my case.

I'm sure the cost goes up with the more bolts that need to be extracted.
 
I had a single exhaust manifold bolt broken on each side of the engine in my EXT.

I had my mechanic replace all of the old bolts and install new exhaust manifold gaskets on each side.

I'm glad I had the shop handle this repair since even to get the already broken bolts extracted, they had to remove both exhaust manifolds and all of the remaining bolts.

Several more of the remaining old bolts broke upon removal and had to be extracted, as well.

Since I am not able to weld anything at home, I would have been in a pickle if I had tried to handle this repair on my own.

And that $500 you mentioned would have been a bargain in my case.

I'm sure the cost goes up with the more bolts that need to be extracted.
Oh so I should just get the new manifolds to Install since they will have to take it off to get to the one bolt... did u go stock or performance manifold?
 
Another option is the clamp-repair, check out the dorman product 917-142. It is made for exactly this. You don't even have to remove the broken or existing bolts for this method, clamps right above using empty holes already on the motor. https://www.dormanproducts.com/p-75506-917-142.aspx


On my 2010 I also have 1 broken exhaust manifold bolt on each side of the motor, both are the closest ones to the firewall. The ticking noise subsides as soon as the manifolds warm up and seal, for now.

As to your question if you want to tackle this yourself, watch a few youtube videos and see what you think about the bolt extraction portion of the job. There are many tutorials as it is a very common problem. If you can handle extracting broken bolts (decent welder?), you should be able to accomplish the rest. Here is a one such video:
 
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Just replace gasket and bolts.

Only replace manifold if cracked.
Common issue the broken manifold bolt.
 
I also had 3 snapped off manifold boots that I fixed myself. The hard part was removing the flange nuts. Broke a few tools on them. P B Blaster and heat helped along with 2 days soak time. Once the manifold was removed, there was enough bolt sticking out i used a small pair of vice grips to remove them. Got lucky.....Took awhile to get them out. Took me 2 days to finish the job. Replaced all bolts with new and swore i'd never cuss like that again. I do all my own work and crawling under the truck 200 times was tough on this retiree..take your time and have plenty of it. Fun stuff....this is a "cold pack " job.
 
Oh so I should just get the new manifolds to Install since they will have to take it off to get to the one bolt... did u go stock or performance manifold?

The original stock went back on.
 
Another option is the clamp-repair, check out the dorman product 917-142. It is made for exactly this. You don't even have to remove the broken or existing bolts for this method, clamps right above using empty holes already on the motor. https://www.dormanproducts.com/p-75506-917-142.aspx


On my 2010 I also have 1 broken exhaust manifold bolt on each side of the motor, both are the closest ones to the firewall. The ticking noise subsides as soon as the manifolds warm up and seal, for now.

As to your question if you want to tackle this yourself, watch a few youtube videos and see what you think about the bolt extraction portion of the job. There are many tutorials as it is a very common problem. If you can handle extracting broken bolts (decent welder?), you should be able to accomplish the rest. Here is a one such video:
I installed it and didn't change the sound still sounds like a hemi truck... that's y it makes me thing there's a leak in the manifold.. thinking if performance manifold with be worth it
 
DId you replace gaskets?
 
They want to charge 500 to change the gaskets at the shop.
It will be a trial and error type of thing ad they didn't check if there's leak just went off by the one bolt missing but I have the doorman clamp and it still sounds like a hemi
 
$500 for exhaust manifold gaskets?

HOLY RIPOFF BATMAN!

Parts cost $6 - $12 at rock auto

Maybe an hour per side... You can do this if you have hand tools
 
$500 for exhaust manifold gaskets?

HOLY RIPOFF BATMAN!

Parts cost $6 - $12 at rock auto

Maybe an hour per side... You can do this if you have hand tools
Yea tell me about it.. problem is getting the bolts that r stuck out, well one but they said usually more will break when u take them out.. 250 a side.. I think it's the same price to just add the new manifolds
 
So I got the clamp installed and it seems to have worked. The ticking sound in the engine bay is gone. Problem now is that I hear a ticking sound when walking around. Could that mean there is another exhaust leak somewhere in the system?
 
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