When I was changing out my IAC valve, I pulled the throttle body and decided to remove the screws that hold on the IAC valve chamber to the bottom, so I could clean all the passages. One snapped off, so I can not remove that screw!! Anyone had that issue and know how to proceed? Looks too small for an 'easy out'. Can I remove all the other screws- providing they don't break(!)- and simply unscrew the plate around that one screw shaft until I can lift it off and then remove the screw with vice grips? Sound feasible??

 

This is common for throttle bodys that have coolant runing through them. All the ones I have had break off are not flush. You can soak down the other bolts with pb blaster and while unscrewing them if the bind screw them back in and out to loosten the crud in the threads. Do not do this more than a few times on a bolt if it doesnt come go on to the next and come back to the one you just worked on. The friction from working the bolt will cause thread or bolt damage. You can heat up the heads with a propaine torch to help free them as well. Once you remove them use anti-seize on new bolts.

 

use vice grips on the studs left once the heads break after you remove the coolant iac plate.