Steel bolts that have been sitting in aluminum for twenty years without anti-seize protecting the threads do not respond to PB Blaster. I was removing my throttle body this afternoon to do a twenty minute replacement of the throttle position sensor, and the top two mounting bolts spun out easily and the bottom two snapped off. So now my twenty minute job is stretched to a few days while I remove the plenum, drill out the broken bolts and install STUDS!

 

if you still have nubs sticking out you can get them with some patience. Use alot of heat and some locking pliers. They should come out depending on how much is sticking out and the quality of your vice grips.

 

It has been my experience that bolts that twisted off when gripped by the head with a good socket are VERY unlikely to come out when gripped by the nub with vice grips. I'd say it's worked maybe 1 out of a hundred times for me. And it DIDN'T this time.

 

It has been my experience that bolts that twisted off when gripped by the head with a good socket are VERY unlikely to come out when gripped by the nub with vice grips. I'd say it's worked maybe 1 out of a hundred times for me.

If you're trying it without heating em first I'm not surprised it doesn't work for ya very often if at all!

 

Thats fine, if i were you i would just buy a new upper intake and save some hassle. I found some locally when i had a similar problem. I actually have an extra 5.8 upper intake laying around that i dont need...

 

Drilling and tapping will run me about $20 at a machine shop. It's much better than doing it my self. I NEVER get the bit to track straight when drilling out busted bolts and studs! Even when I start with the smallest bit and work up.

 

I have the upper manifold off and will get the broken bolts out tomorrow. Dang thing REALLY makes me appreciate Chevy's old TPI system and its ease of maintenance.