Broke Rocker Arm Bolt During Gasket Replacement

[Papi1]

I recently learned of the problem these vans (1998 Pontiac Transport – Montana Edition) have with their intake gaskets. The van was starting to weep coolant (~185 000km). As such, I was replacing my lower intake manifold gaskets over the weekend. Everything was going quite smoothly (despite the obviously ridiculous disassembly routine). The lower intake gaskets definitely needed replacement, but were not as bad as some people have had. The gaskets were replaced and reassembly was starting. Then wham. One of the rocker arm bolts broke on me. Actually it was a family mechanic who was using a torque wrench and tightening them to 168 inch-pounds. He clearly screwed up and now has me seriously questioning his qualifications (nope, I’ve just thrown them out … I’m tightening every bolt from now on). I won’t rehash the my rant any further. To the crux of the matter then …

The bolt broke such that no part of protrudes from the head … its essentially flush with the surrounding surface. I’m not quite sure how to proceed from here … there are some options:

1. Take out the bolt using a broken bolt/screw remover drill bit - with the head in place on the vehicle.
2. Take out the head and then remove the broken bolt.
3. Take out the head and give the work to a machine shop.

I have taken broken bolts out before and know the routine fairly well; but in this case I am concerned about the fact that the bolt (steel?) is broken in an aluminum head. Are there any special steps I should take or issues I should be concerned about. I don’t want to exacerbate the problem any more.

Any thoughts?

[LMP]

That is a 3.4 hey? I hate that engine...I think GM should have kept the 3.8 beast all the way. I wonder if they did that to lower the "average" corporate advertised MPG but my experience is that the 3.8 burns less anyway at highway speeds.

In regard to your problem - I think you have listed the options in proper order and caught with the same problem, and cautious as you mention not to exacerbate the problem, I'd certainly try 1...hoping not to have to fall back on 2, expecting not to have to resolve on 3. Please keep us posted on how it turned out.

[richtazz]

If you can get a dremel tool with a cut off disc on the bolt, you may be able to cut a small slot and turn it out with a flat head screwdriver, since the bolt is a harder material than the head. Other than that, follow your own steps in order.

[wilfie27]

You probably would want to lay some rags around the area you are working to prevent shavings from falling into the motor.

[Papi1]

Well it was fixed way back in early september. It was not possible to remove the bolt while the head was still on. Kept going and took off the heads. Good thing too as the head gaskets were going to need replacement soon.

Drilled through the bolt and eventually was able to get it out with minimal (or negligible) damage to the threads.

It may just be me ... but the engine seems to be running a lot quieter now.

During all this I noticed that there was a good amount of residue built up in the engine. I've been doing oil changes on time and using synthetic oil. Not sure why that was occurring.