Engine Cooling problem
2001 Kia Optima 4 cyl Front Wheel Drive Manual 99275 miles
I reciently had my oil changed and the car was running fine. I was driving down the road and my temp went from normal to hot in seconds I have look for leaks and cracks and found nothing but it is still overheating and I dont know what it is
Find the thermostat and replace it for a start-that don't work do below
Have it block and pressure tested-do the block first to pinpoint a combustion leaking into the cooling system or a gas analyzer to sniff for hydrocarbons at the radiator fill neck.
Pressure test: do not do a pressure test if there's leakage at the headgasket this might cause coolant into the cylinders and lock it up or bend a connecting rod if cranked thereafter. The headgasket should be repaired before doing the pressure test.
If the block and pressure test passes check the following: Thermostat, Pressure test the Rad. Cap, Clogged radiator, Fan clutch, Radiator electrical fan, collaspe hoses, water pump.