over heating

[z28z11]

I've had a cracked head do this once upon a time ago - wild swings in temperature on the gauge, luckily found the problem before it really got worse. Had this happen on a late model V6, Impala motor, head gasket gave up the ghost at the edge of one cylinder - just a little bubble in the gasket, but drove me crazy until we pulled the heads off to check 'em.

Good luck, tell us what you discover -

Regards,
Steve

[pjbizjak]

OK guys first off thank you for all your feedback! With a little more basic mechanics I removed the thermostat and lower hose then did a complete flush of radiator and block three times until water stayed clear and ran motor for more than 15 minutes without overheating. installed new thermostat 180* and 15# rad cap. Things seem to be normal now but I'll wait until I take the car on the road to see what happens. Oh, not sure if I have the correct temp sensor, anybody have correct part number?
once again thanks;
Pete

[pjbizjak]

Todd, Yes the heads were redone new valves hardened exhaust seats, seals, springs, guides etc. block was bored to 40 over, crank cut 10/10, new J&E pistons, new bearings rings oil pump and all seals. Cam is comp cam = to original 30/30 duntov, lifters, rockers, push rods etc. Refreshed 780 cfm holley 1111480 distributor set up by Jerry mcNeish.

[firstgenaddict]

When the car is at operating temp and you cut it off... what does the fan do?
Does it stop almost immediately?
Does it continue to spin?
A PROPER FUNCTIONING FAN CLUTCH WILL NEARLY STOP THE FAN IMMEDIATELY WHEN THE ENGINE IS KILLED (less than a single rotation) if it continues to spin it is not drawing enough air, I thought mine was ok until it was rebuilt... it's like a tornado now!