So, I decided to tackle the spark plug replacement DIY today. Everything went well until I was buckling down the last ignition coil and the 10mm bolt snapped. Apparently my torque wrench has stopped working correctly (stopped giving me the audible click - I have checked it since, and it for sure gave out). I have tried making a groove in the top and backing it out by hand, no luck. I then went on to try Grabit SpeedOut bits to try an engage it and back it out that way. The tip of the bit broke off engaged into the bolt. I'm out of ideas. I've never had this much trouble getting a bolt out. Does anyone have any ideas? Should I just take it in at this point? Is it safe to drive with the coil not bolted down completely (short term)? Pictures for reference:

 

To fix it right, grind down the metal casting down to level it along with the remaining end of the bolt. The bolt surface needs to be flat to get a drill in the there and centered. Then pick your poison...reverse drill bits, easy-outs, etc etc.

But, to get by in the meantime, ZIP TIES to hold it down.

 

If you grind down that surface, measure the height loss and insert a spacer to make up for that loss. That will keep even pressure on the coil; otherwise, it will be bolted down cockeyed. Do be careful hammering with a pick less you crack the alum intake.

 

If the bolt is not needed for a ground I would just push it on the sparkplug and drive it. If it runs ok, Great. But if a ground is needed you may have to make some type of ground strap. To drill out a bolt and re-tap the threads could be tricky.

 

If the bolt was not cross threaded it might come out easier than you think. I would either crazy glue something to it and try to spin it out or try to make a small notch and turn it out with a small screwdriver

 

Thanks for the input everyone. I tried backing it out with a few different methods to no avail. My mechanic said it wasn't worth the risk at this point to get it out, as if the aluminum head gets damaged that's going to be expensive to fix, and risk to benefit is minimal. He said to just drive it, worst case scenario is the pack pops up at some point and I get a misfire. If that happens just push the pack back down. If it happens consistently, then he'll look into trying to fix it. I have been driving it all week (70+ mi round trip) to and from work. So far no issues. There is a bolt near the coil that I might use to hold some sort of metal "arm" that will keep some slight pressure on the pack, just to be sure, but that is likely overkill at this point. Luckily the bolt was purely mechanical retention for the coil pack and not a ground, so we should be good there.

 

Pretty sure your going to be ok.