TROUBLESHOOTING BASIC COOLING SYSTEM PROBLEMS

The most common troubles you'll have with your car's cooling system will show up as overheating. They will first show up when the high temperature warning light (on the dash) comes on or when the temperature gauge shows abnormally high operating temperatures (above 230°F). Occasionally, a weakened hose will rupture and cause immediate overheating.

YOUR CAR'S ENGINE OVERHEATS BECAUSE ...	YOUR CAR'S HEATER DOES NOT PRODUCE HEAT BECAUSE...	YOUR CAR'S ENGINE WARMS UP SLOWLY BECAUSE...
COOLANT LEVEL IS LOW Check and correct level	THE THERMOSTAT IS STUCK Replace the thermostat	THE THERMOSTAT IS STUCK OPEN Replace the thermostat
LOOSE OR BROKEN FAN BELT Tighten or replace fan belt	THE HEATER CORE IS CLOGGED Have the heater core checked
FAULTY RADIATOR CAP Replace cap	HEATER CONTROL IS FAULTY Check the control mechanism
INACCURATE GAUGE OR WARNING LIGHT Have gauge and sending unit checked
CLOGGED COOLING SYSTEM Drain coolant and flush system
DEBRIS ON RADIATOR Clean the radiator
THERMOSTAT STUCK CLOSED Replace thermostat
WATER PUMP IS FAULTY Have water pump checked and/or replaced
ANTIFREEZE HAS BEEN USED TOO LONG Drain coolant and fill with fresh mix
WATER HAS HIGH MINERAL CONTENT
RADIATOR HOSE HAS WEAKENED AND COLLAPSED Replace hose
IGNITION TIMING IS RETARDED Check and set ignition timing
ENGINE OIL LEVEL IS LOW Check and refill engine oil
CYLINDER HEAD GASKET LEAKS This is usually accompanied by bubbles in the radiator (engine running) and poor compression in the cylinders adjacent to the leak.

TROUBLESHOOTING BASIC COOLING SYSTEM PROBLEMS