1999 Chevy Blazer is running with no engine problems. Oil was changed 800 miles ago and oil on dipstick is clean and appears normal, no antifreeze odor. The mechanic made no comments when he changed the oil. Antifreeze in overflow and in radiator is clean. Two days ago my engine temp starting rising above normal and my heater would start to blow cold. Engine does not overheat and after about 30 seconds the temp drops back down to normal and the heater blows warm again. This keeps happening. Changed thermostat and when old thermostat was removed the fluid was sludgy black, looked like dirty engine oil. Engine still runs fine but the temperature and heater cycling is still there with the new thermostat. I have an appointment tomorrow to get the cooling system flushed. Do I have a serious issue coming up?
Feb 12, 2008 at 10:44 AM