@#$%! Valve cover bolt broke off in head (99 GTP)

[DrRadar]

I was trying to be perfect...got a loaner "click" style torque wrench from local parts store to torque down valve cover instead of using my very long "needle" type torque wrench with 10 ft-lb intervals. Dialed in 89 in-lb and...snapped not one but two bolts waiting for the damn click. I should've have realized that was too tight.

I was able to drill a pilot hole in one and use an extractor to recover one. But couldn't get the pilot hole centered very well on the other and the extractor wouldn't turn the fragment. Drilled it out, but now virtually no threads in the hole.

I'm looking for some guidance on how to repair. Looks like the valve cover bolt holes in the head may already be helicoiled. If so, how do I replace the helicoil? Would rather not tap to a larger size and have a different size bolt.

Another self-inflicted wound...crap.

[aleekat]

Just a guess. Maybe fill with some JB weld and tapped out to original thread. FYI, after the fact. Did the same thing many years ago. Old Mech said never use torque wrench on valve covers or thermostat housings. Just kinda "snug"..

[rustydogy]

I go with alkeekat tork specs are only meant to be met once as that is the stress limit of a bolt

[Lukas111]

Put bolt on top and weld through the middle to broken screw and then unscrew it, go to junk yard and get one screw.

[DeltaP]

Originally Posted by Lukas111

Put bolt on top and weld through the middle to broken screw and then unscrew it, go to junk yard and get one screw.

I think you mean... Put nut on top and weld through the middle to broken screw and then unscrew it. Yeah, and they used to make rods for just that. Haven't seen or used 'em in years. (bolts don't snap on me...ha,ha). In lieu of welding equipment I'd just tap new threads to the next size in metric or inch worth, whatever is closer. You'll be drilling out way too large with a new,next size helicoil. It's only a valve cover bolt after all. No critical movement of parts.

[DrRadar]

Put in a helicoil. All's well that ends well...but I don't wanna ever do that again.

[DeltaP]

Good to hear you got it fixed. Thanks for letting us know.

[rkvons]

Originally Posted by aleekat

Just a guess. Maybe fill with some JB weld and tapped out to original thread. FYI, after the fact. Did the same thing many years ago. Old Mech said never use torque wrench on valve covers or thermostat housings. Just kinda "snug"..

I used to snug my transmission drain pan bolts, but never knew if they were right. So I tried using a torque wrench once. I put all of the bolts in by hand as tight as I could and then I went to the torque wrench. On the very first bolt, I snapped it off. I was able to get ahold of the bolt sticking out. Lucky me. I think these bolts fall into the about category and will be "snugged" from now on.