i have an lq4 thats going in my silvy and it has the rear two exhaust bolts broken off. they're not way below the mani surface just a turn or so. can i still reach them? should i "stack some" weld on it first or just fill it. how much can this hurt the head? thanks guys

 

If the engine is out I'd try a chisel in the center & try to back them out with a screw driver..

 

how about trying an extractor to pull them out

 

Your saying below the manifold surface, you mean face of the head?? If it is broke off a few threads into the head, it can only melt the aluminum, still be cleaned up.. You really only need some threads to hold the flange on.. Try to get down to head of the broken bolt, clean it to shiny new metal again, then have at it..

 

Pull the manifold,get a few 7/16'' nuts and fire up the mig pretty hot.I had to do this with the motor in the truck a few months ago, caught the firewall insulation on fire twice. With a lot of cussing I got the nut welded to the broken bolt on the third try and she backed on out. Good luck.

 

yeah it's out with no mani on it now. broken just below the surface. i'll try fishin it out with a pick, but i am sure i'll be hittin it with the welder.

 

Use an arc welder. Build up the bolt some and then weld the nut to it. I've done this several times. Arc welder definitely works alot better then the mig.

 

i unfortunately do not have a stick welder. good to know that you have had luck with this though

 

I just did this on my brothers Suburban over the weekend. I used a mig on a lower heat setting and slow wire speed. I did about 1sec bursts letting the fill cool back to metal color then hitting it again until enough was built up outside the head to grab it with a female extractor. It didn't get hot enough to damage the head at all.

 

sweet, thanks bigkid