Im working on the plenum gasket replacement, and sooo much of my bolts are corroded. I wound up snapping the #1 bolt in half and halted the project. A few questions follow that snapped bolt. #1, are the bolts aluminum? #2, the bolt broke about 2-3mm into the threads, so will it still hold the torque and prevent a leak if I just button it back together? #3 are there any other options besides drilling and tapping? thanks for the help.

 

Take it to a nearby shop.. I had the same problem happen with my 84 Chevy... They just took the torch to it, heated it up and never ruined the threads.. 40$ and the bolt was out. Ofcourse you could do it cheaper yourself, I just didn't want the hassle.

 

That's if any of the bolt is sticking out of the block***

 

They are aluminium, did you get new bolts for the install? I tried to get mine out with an easy-out but it broke and caused a PITA because it was much harder steel then the soft bolt. If you don't use a cheap made in china easy-out likeI did you willprobably get it out.I ended up drilling right through the centre very carefully and cleaned it out with a tap. I wouldn't leave it, you will regret it if it leaks and you end up having to do it all over.

 

Yeah, there's multiple ways to get the bolt out, i've even seen pieces of scrap metal welded onto the bolt so that it can be twisted out.. However, it all depends on where the bolt broke, and if it was flush or not. Also like 982500Ram said, breaking an easy out is not a fun situation to be in =] Good luck to ya.

 

If there's enuff of the bolt sticking out use a chiseland hammer and slowly work it around

 

I broke three of mine while doing the plenum. I drilled and used an easyout. Tension was high and lots of Oh ***** as they snapped. After I drilledthe center,I soaked them again in PB and allowed them to cool. As usual, once the pressure of the head was off the bolt, the stud came out pretty easily. Maybe I was lucky. If you are not comfortable, bring it to a shop. If the easyout snaps, the job gets much tougher.

 

As someone with a lot of experience with broken bolts on my '41 Buick Century restoration project, something that always works for me is welding a nut onto the broken stub, then using that to back it out. The heat of welding is as good or better than a torch, and the nut gives you something to grab with your wrench. Use a really scabby nut and make sure the broken stub is really clean--you want it to bond to the stub better than to the nut. The possibility that these bolts are aluminum (are they really? I've never heard of an aluminum bolt that could possibly be strong enough to hold engine parts together) can make welding more difficult, but not impossible.

I also have drilled out the center of the bolt with progressively larger drill bits until there's just a slight ring around the perimeter that protects the threads--you can back that out easily with an EZ-out or a reverse tap. Then clean up the threads with a properly sized tap. I would try this before making a small hole and using a small EZ-out--get the hole as big as you can without damaging the threads before going that route. Sometimes the bolt will even crack when the hole gets big enough and will come out easily. Use care drilling the hole--it isn't that hard, but make sure you keep it straight anduse a slow drillspeedwith lots of oil (PB Blaster is my favorite).

Hope this helps!