Broken Exhaust Manifold Bolt

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Char

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The front drivers side exhaust bolt snapped on my suburban. It is snapped well into the cylinder head, nothing to grab onto. I had a mechanic try to extract it, no success. His plan is to take the cylinder head off and bring to a machine shop who would drill it out.

Also, the manifold is warped, so the second bolt from front on the drivers side would not fit when reinstalling the manifold. Only putty/paste is sealing that front flange.

At least this gives an excuse for replacing the intake gasket, which I was worried about. Any other preventative maintenance I should get done while the engine is all opened up?

How urgent is this fix? I was thinking I would get it fixed once it starts getting noisy.

Any other ideas let me know
 

Joe Dirte

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Passenger head on my new/used 350 had bolt snapped off flush at the rear. After a couple failer attempts and a trip to ER my friend was able to drill it out, then tapped n helicloil with plenty of sever duty loctite, let it ait for few days then reinstalled with new headers. Fingers crossed. So far my dude did an awesome job. If it comes out again im just replacin head.
 

Moparmat2000

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Broken off inside with no protruding bolt at all, yeah, to the machine shop.

For re-install of the manifold you need a Lisle #13000 manifold spreader tool. Just about all of these cast iron manifolds are like this.

Richard
I would imagine trying to spread the cast iron like that to put it together and the manifold trying to return to it's current dimensions will put pressure on the new bolts you will be putting in and eventually snap those too. I am betting that's how it snapped off the first time. A sideways load from the manifold pushing against the bolt. Once you get that tapped hole fixed in the head, I would recommend another exhaust manifold that's not warped or put shorty headers on it. They are cheap enough these days.
 
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someotherguy

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Haven't experienced any issues with broken manifold bolts even after fighting some ridiculously warped manifolds. Surely it's possible, just doesn't seem like a common occurrence on these engines though, for whatever reason.

Super common on LS's apparently..

Richard
 
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