QuestionJust bought a 1995 chevy lumina at auction, Car keeps overheating. replaced the thermostat, still overheats. both electric cooling fans are working, looks like car sat for a while before i bought it, when i replaced old thermostat, there was a chunk of what looked like...white calcium deposit about the size of a pea. crumbled in my fingers. no other engine problems. no coolant in the oil. no leaks, tried burping out air bubbles. any ideas?
AnswerLook for a collapsed hose. A bad hose will squeeze shut.
If you bled bubbles at the bleeders and got great pressure, then water pump is working.
Inspect the radiator for damage. If you see a place where damage may have occured, then watch for BARSLEAK that could have plugged the system.
Try removing the thermostat and perform a cooling system flush. Then replace the thermostat and see if that helps. If you see lots of rust, the radiator is probably bad (plugged).
Did you use the correct color antifreeze? Red or green?
Is the heater core bypassed or other areas look like the system has been altered?
The heater core could also be plugged. This will appear like a plugged radiator (rust). TO test, disconnect the heater core and bypass it. If overheat stops, then this is it.
Try a less poundage cap.
Last case, suspect the radiator.
