hello i searched this board and i see a lot helicoil and tapping etc talking abouit for stripped threads and when i went to auto part store to get a tapping kit which i need to fix threads once i get bolt out but i cant get the valve cover off got 3 they off but last one just wanst to turn and turn someone told me stick screw driver under it while turning no luck with that should i try drilling near it make hole wider? just break it off and just put new valvle cover with 3 bolts or will this cause leak most likely? thanks ior any help

 

Did you try locking vise-grips on it and pulling up as you turn?

 

Nevermind, I understand what happened now. I wonder if there is room to try turning it with vice grips so you can pull up at the same time...

 

Try putting the screwdriver between the SIDE of the socket and the valve cover and and twisting the screwdriver handle to applysome gently pressure SIDEWAYS on the bolt as you turn it. Sometimes it will force the bolt to grab just enough meat in the remaining threads to be able to unscrew it.

 

You can also try heating the head of the bolt slightly with a propane torch so it expands the metal and causes the threads to grip better. This old croation machinest at my work told me that. Just be careful not to over heat and weaken the metal too much or it will break.

 

Dremel tool with a cut off wheel... cut a slot in the head, and use a screwdriver to take it out.

 

I think it is the threads that are stripped, not the head of the bolt. It turns but doesn't come out.

 

go to sears and get these great things called EZouts

 

thanks everyone for their help i used a blow torch heated it up and then pulled it off with vice grips thanks for the suggestions