Finally had some time to complete the head gasket. Now I’ve run into a new issue. Was going through the last stage to torque on my head bolts and this bolt snapped. These are brand new felpro any tips on what to do next? Do I have to remove the head again and get a new gasket? I believe it’s an MLS gasket. This Gasket

I saw that someone had this happen to them in This thread. He had drilled into it with a 1/8” bit and hammered a 1/8” Allen key and got it out on a 96 s10 4.3 without having to buy a whole new gasket kit.
i was thinking of flattening it with a transfer punch then drilling it with a left handed bit and maybe trying to get it out that way or an extractor? I’m pretty stuck at what else I could do. I must not have chased the thread far enough or maybe I missed something when blowing that one hole out. I have no idea. I’m also assuming they don’t sell a single head bolt, so would i be able to clean up one of the old ones and add sealant? Would this happen because I did the 3 stage torque method 25-45-65? My torque wrench was definitely not off.

snapped head bolt

The manual I used had that as the torque spec but I've seen the 2nd gen have a different torque method where they torque All bolts first sequence 22 ft. lbs. then Long Bolt Final Pass in Sequence 75 degrees, Medium Bolt Final Pass in Sequence 65 degrees and Short Bolt Final Pass in Sequence 55 degrees.

 

I'm guessing you re-used the bolts? Or didn't spend the money for quality replacement bolts? Rule of thumb, never reuse any bolt that requires a certain amount of torque. The bolt stretches to attain that torque setting. Once stretched, and you reuse it, it has to stretch more to attain that torque setting. As it stretches more, it weakens until it breaks. Hopefully, there is enough of the broken bit to get a pipe wrench on it to back it out. If not, you could drill it out and try an easy out. If that fails, welding another bolt onto the broken should work.

Make sure you replace all of the other bolts so it doesn't happen again. Oh, quality bolts such as ARP.

 

Ya they were new bolts. Felpro was what the parts store had so i got those. I must have not chased the thread far enough or maybe i missed that one not too sure really. I asked for ARP originally but they didn't carry them at the 3 places I looked at. Only way I found them for a 4.3L was to cross the border into Buffalo and pick them up there. Anyways, ill have to drill out the bolt and pull it with an easy-out hoping that works.

 

If you remove the head there maybe enough of the broken bolt protruding from the head that you can grip it and remove it easily. I would do that route before i resorted to drilling the broken bolt, If it broke off flush with the head your options are limited,. Another option is to grind down the end of the broken bit on a taper. Than weld it to the broken bolt and remove it with a wrench.

 

Thanks! I ended up just taking the head off. There wasn't enough of it sticking out to turn out. I used a dremel and made a small divet to help the drill bit from walking too much. Drilled a few mm with a 1/8 bit and then turned it out with an extractor.

 

 

That is a big relief to get the bolt out without any damage to the existing threads. Good job.