This is the way to go if you can get in there. I just got my 04 LQ4 and that same bolt was broken, Im wondering if it happens on the production line sometimes. Too bad you didnt notice it while it was under warranty

 

If that doesn't work, just pop the head off. its 20 minutes from where you are at now. Take it to a machine shop and give them $15.

ohh yeah, PB blast the **** out of it before trying anything. Maybe even heat up the bolt too (careful, PB will catch fire. heat it up first, then PB blast!)

 

Unfortunately this is a very common problem on these motors ( saw the same thing x2 ) and is in the worst place to fix on the vehicle.
Best bet is to try what 5.3 suggested else pull the head off.

 

I have 3 that broke on me. What do you guys connect the grounding clamp to?? Will it toast the sensors with them in the block if I connect it to the block?

 

I have used this trick a couple times and I like it cuz it works. What is the purpose of the wax? I may need to keep some handy.

 

thread lubricant.

 

Just put Gibson Shorties on my 99 Silverado w/5.3. Found the same problem,last bolt on drivers side broken flush with the head.The exhaust manifold didn,t leak so I put the header on like it was,so far no leaks.

 

I bet it was the same moron on the assembly line that was doing it all .

 

ya, I just went ahead and bolted mine back up. The bolt actually was broken a little in the head and I was able to cut a bolt and get like two threads to grab. (I don't really think it made a difference though because I didn't want to torque it too much and strip the threads). I do hear somethig making a pht pht pht sound on the drivers side and will have to tear back into it when I get a chance.
Thanks for the suggestions though....