: Broken Head Bolt (small type)

04-06-06, 09:54 AM
I can't explain it the torque wrench was set to 10 ft/lbs like it says in my manual and the broke this bolt. (There was some debate it might have been bumped up to 12 ft/lbs accidently cause my brother broke the bolt)

Please see photos. Second photo is just so you know what's installed.

The bottom and middle bolts torqued OK and then a POP sound and that was it. Must have been a fatigued bolt, (of fatigued operator) I guess I should have replace them. Too late now.

My first question is has anyone run without one of the small bolts before ?

I plan on putting performance heads on in the near future 6 to 8 months (no more that a year) with MLS gaskets.

I'm very eager to get this back together should I deal with it now ? or later when I put the new heads on ?

TIA Jaxx

04-06-06, 10:37 AM
Now, not later.

04-06-06, 11:47 AM
I forgot my service manuals at the shop and was so upset I didn't bring home the broken bolt to measure it.

Can someone please post the thread size ? Out of memory I think it was an M5 or M6 but looking at a setup calipers makes me think it's an M4.

I need to start shopping round for a small screw extrator.
TIA Jaxx

04-06-06, 12:29 PM
did it have oil on the threads?

04-06-06, 01:07 PM
If the bolt was overtightened and pulled in two you should be able to twiddle it out with a sharp awl or scribe. If you can budge it at all with a sharp instrument you are home free. You can also try nudgeing it a little bit with a very small and sharp center punch. Tap the punch with a very small hammer along the edge of the bolt in such a way as to turn the bloody stub out. Go easy and don't beat up the end of the bolt. Drilling and extractors is the absolute last resort.

04-06-06, 04:25 PM

No oil everything was very clean, Just finished timserting whole block, machined heads to clean up the leak area.
Previous thread about if you interested: http://www.cadillacforums.com/forums...ss-up-ecu.html
I sprayed all the wholes with barke cleaner and blasted them out with 140 psi of air.

I was just getting ready to put the intake & water pump back on when this happened.

Off to the Stealership for some bolts ( I love that saying, first saw it posted by PJs)