A vehicles cooling system is critical to the operation of the engine. If an engine continues to run in an overheated condition, it could cause severe damage to the engine and cost thoudands of dollars to repair. It’s important to learn the basics of a vehicles cooling systems operation before trying to fix a cooling system problem.
Basic Steps to Diagnosing a Cars Engine Overheating Condition
These are basic steps that the average car owner can take to find and fix a problem with the vehicles overheat condition. If the problem cannot be diagnosed using the following steps a professional automotive technician should be consulted.
Check the Engine Coolant Level
Check the radiator or expansion tank (if equipped) coolant level. Never remove a pressurized coolant cap when hot, it could spray hot coolant and cause server injuries. If the coolant is low, add the recommend mixture of coolant. Run Engine and recheck coolant level. If the coolant is low there’s a good probability that there’s an internal or external leak.
Coolant Condition
- If the coolant hasn’t been changed as scheduled, it could loose it strength and boil over easily.
- It could also have an excessive amount of rust and other contaminants that can block coolant passages in the engine and radiator. A coolant flush may help to eliminate the problem.
Check for External Leaks
Visually inspect the radiator, radiator hoses and heater hoses for leaks. Visually inspect the engine area, for any signs of coolant leaks. If there are wet spots on the front floorboards of the interior or the windshield fogs up when the defroster is on, the heater core is probably leaking.
Check for Internal Leaks
- Look and see if there’s an excessive amount of white smoke coming out the exhaust tailpipe. This is an indication of a bad head gasket.
- Pull the engine oil level indicator (dipstick) and see if there is a milky color to the engine oil. If coolant is in the engine oil, this is an indicator of serious engine damage.
Check the Operation of the Thermostat
A thermostat that is stuck closed will cause the engine to overheat. To test if thermostat is stuck in the closed position, place the thermostat in boiling water. If the thermostat doesn’t open, than the thermostat is defective and needs to be replaced.
Check the Engine Coolant Fan
Since the cooling fan pushes air through the radiator to cool the coolant, a fan that’s not working properly will cause an overheat condition.
- Electric Fan – If the vehicle is equipped with an electric cooling fan, check to see if the fan is working properly. Most electric fans will only operate when the coolant temperature reaches a certain degree. In many vehicles when the air conditioner is turned on, the electric fan automatically turns on. The most common cause of an electric fan failure is the fan motor, a controller module or a relay.
- Engine Driven Fans – Some vehicle have cooling fan driven off the front of the engine. If the clutch (between the fan and the engine) is bad it may slip. If the clutch slips it may not allow enough rotation on the fan to be affective and the clutch needs to be replaced.
Check the Radiator
Some radiators are mounted on the front of the vehicle (especially rear wheel drive vehicles) and road debris could damage the radiator. Also there may be an obstruction to the radiator like newspaper or cardboard that could block the radiator. The radiator cap could also be bad and not holding pressure. In order for the cooling system to function probably a certain level of pressure must be maintained.
To help insure that a vehicle is in top running condition, it’s imperative that the vehicle adheres to a routine vehicle maintenance schedule. If the vehicles brought in to an auto shop for a cooling system service or flush, ask the service advisor if they check the cooling system pressure as part of the service. A cooling system pressure will help to insure that there are no other problems with the cooling system and give the driver a little more peace of mind on the road.
James Clausen - Clausen received a Bachelors Degree in Business Administration in Automotive Management and Marketing at Northwood University, graduating ...
Join the Conversation