How to Maintain Your Vehicle in Hot Weather and Prevent Overheating

Engine overheating is one of the most destructive events that can happen to a vehicle, and unlike many mechanical failures, it is almost entirely preventable with proper maintenance and attention to warning signs. Understanding how cooling systems work, what causes them to fail, and what to do when they begin to fail prevents minor problems from becoming catastrophic engine damage.

Prevention Through Cooling System Maintenance

Check the coolant level in the overflow reservoir regularly, particularly before long trips in summer. The level should be between the minimum and maximum marks with the engine cold. Low coolant level is the most common cause of overheating and the most preventable. If the level drops consistently, there is a leak that requires repair. Have the cooling system pressure tested to identify the leak source.

Thermostat and Water Pump

The thermostat regulates coolant flow and opens when the engine reaches operating temperature. A thermostat that sticks closed prevents coolant circulation and causes rapid overheating. A thermostat that sticks open prevents the engine from reaching operating temperature and reduces heater output, but does not cause overheating. The water pump circulates coolant throughout the system. A failing water pump may produce a squealing noise, coolant leak from the pump weep hole, or reduced circulation that appears as gradual temperature rise under load.

Radiator Condition

The radiator transfers heat from the coolant to the ambient air. A radiator with clogged tubes, bent fins, or accumulated debris between the radiator and condenser has reduced heat transfer capacity that may be adequate under normal conditions but insufficient in extreme heat or under towing loads. Have the radiator inspected visually for fin damage and cleaned of debris as part of pre-summer maintenance.

What to Do If You Overheat

If the temperature gauge rises significantly, immediately reduce engine load by turning off the AC. If the gauge continues rising, pull over safely and stop. Do not continue driving with an overheating engine. Even a mile of driving with a severely overheating engine can warp cylinder heads, blow the head gasket, or cause complete engine failure. The cost of a tow is always less than the cost of catastrophic engine damage.