I have a 2002 bonneville and I was going thru a drive thru. The car started lightly clunking as I arrived and clunking was slightly louder by the time I exited, then when I gave it gas to go it died and I rolled into a parking spot. When I tried to restart it... nothing at all. When I got it towed home it turned over exactly twice then nothing. First I took the alternator in and tested it (fine), then the battery (fine), then the ICM (junk). So I replaced the ICM and it turned over about 7-8 times then I heard a loud squeak like the belt slipped. So I stopped immediately. When I tried again it turned over twice, then nothing again. I tried a new ignition switch too, that did nothing. So I am completely confused, my friend thinks maybe the computer is bad, I can't seem to read codes on it, nothing shows up even though the check engine light is always on. Any help would be very much appreciated. Thank you

If the check engine is on, you should be able to read the codes with a regular OBDII code reader. That's would be a place to start, to find out what codes you have.

Have you checked that each plug is getting spark? And that your are getting fuel (or rather have enough fuel pressure)?

_________________
Clay
1997.2 40th SLE-138k
1968 Bonneville 400ci w/TH-400-40k
1999 GMC Suburban SLT-191k
2005 Escalade 253k-GINA

Put a wrench on the large bolt on the crank pulley. Can you turn the engine by hand that way? If not, remove the serpentine belt, and try it again. If it moves now, check anything that is supposed to move in the belt path (pullies, a/c compressor, etc.) to see if they move freely. If it still won't move, you may have had an intake failure and the engine has seized.

_________________
*Gone, but not forgotten* - Black 2000 SSEi, HIR Headlights, Angel Eyes fogs, 3rd brake light overlay, hi-flo cat, 180 degree thermostat, HS 1.9 rockers, LSx yellow springs, Intense FWI, PCM, shift kit, push rods, and 3.4 Pulley. ZZP Power Log.

Yeah I was hoping the engine is not seized. I have not tried turning it over by hand yet because of that fear. I just find it odd that it didn't overheat. The temp was slightly above normal, but I was in a drive thru and it was 90+ degrees out. The car had coolant and oil in it. I will check today for possible seizure. And I tested my coils with my multimeter, they were ok. Was hoping it was something simple that has happened to someone else.

Pull the dipstick and look in the radiator, coolant overflow bottle. Do you see what looks like a milkshake? That would be common symptom of intake failure.

_________________
Clay
1997.2 40th SLE-138k
1968 Bonneville 400ci w/TH-400-40k
1999 GMC Suburban SLT-191k
2005 Escalade 253k-GINA

No milkshake. Plus the intake is all new. Just did lower gaskets and a new upper intake this winter.