Advice, insight, rumors?...... I got 9,500 miles on my rebuild and I cracked a head. (I'm way out of warranty) I pulled the bad head off and noticed the following: originally, my head bolts were gold irridated, but they are very blackened. The bolts on the good side are not discolored. Is this indicative of anything?o No: Read on, there's more....
I'm guessing here so don't take my word for it but it could mean a vacuum leak on that side of the intake. A lean condition would certainly heat things up (blackening bolts and cracking heads) on that side of the motor. How did it run for those 9,500 miles? Bill S.
This was a smooth, good running engine. I've got a vacuum guage in the car, and I'd say it was on the low side at idle (12-16in.) but I've got a mild cam. Gas mileage was piss poor-11 ish. The engine never ran hot or sloppily until after the head cracked. I run a temp guage and an idiot light, neither gave me any indication that anything was wrong. I've replaced the head and I've still got a low compression reading in the "bad" cylinder. Can I bench test the block? (I've yanked the engine again) I really doubt I've got a cracked block. I suspect an intake gasket, maybe??? Does anyone make one which isn't tin??? I'm a former Pontiac owner, so these questions may be a bit lame, but I just o No: don't have much knowledge with these cars yet. Any ideas here? I'd greatly appreciate any. I spent a couple of grand on this engine, and I don't want to trash it. I have some doubts about the machinist who did the work, so I'm looking for practical knowledge from people who know. Thanks
Buick recommends putting a tablespoon of oil into the suspect cylinder through the plug hole. Then repeat the compression check. If it comes up it is a ring problem, if not maybe a valve. Worth a try?