My first time with a helicoil didn't go all that well. I did 3 of my exhaust manifold bolt holes. Two of them were fine, the third I couldn't get the helicoil to go all the way in, so a little it sticking out.

My question is whether I can just drill the coil out using the same drill bit, and re-coil it with the same size coil, or if I need to go the next size up now that I messed it up.

I was just going to say "screw it", but I'm getting sick of hearing my exhaust leak!

 

I doubt drilling it out with the tap drill size will work.

What happened did you not tap the threads deep enough??

If you can get a good grip you might be able to pull it the bad helicoil out with good needle nose pliers.

I have a few times.

 

If there's enough of the helicoil sticking out u may also be able to grab ahold of the end of the helicoil with a pair of vice grips and pull it straight out. It will unwind the helicoil in the process and then it will be junk obviously. I've done this a few times in the past and it worked fine. I'm also curious why it didn't thread in all the way. I'm not a huge fan of helicoils in the first place. I find steel inserts to be much easier to work with but honestly I don't know where to get them outside of my workplace. McMaster-Carr or Grainger I spose. We have 3 or 4 different styles of inserts at work along with helicoils as well.

 

Also I believe helicoils are hardened so drilling them out is not a good option.

 

Ok, thanks.

Part of it was that the handle I bought for the helicoil wasn't really big enough, so I couldn't get enough leverage to really cut the threads into the head. That might be why it didn't go in all the way. I bought a bigger handle.

I'd just chalk it up to it being my first time, and I just didn't do a great job.

I'll try pulling it out. Thanks!