Engine - 2010 Nissan Murano 2WD 4-door SEnlarge Photo
You know a heat wave when you are in the middle of one and so does your car. For you it means burning the backs of your legs on the vinyl seat, for your car it’s when operating temperature is reached before you have backed out of the garage.
So how can you insure that the heat outside doesn’t wreck havoc on your car’s cooling system? Think fluid and air. Those two cooling agents can have great consequences on your vehicle’s ability to stay cool during a heat wave.
The fluid we’re talking about is of course anti-freeze/coolant. It needs to be the prescribed formulation for your car. It also needs to exist in the cooling system at correct concentration. The same concentration that keeps your car from freezing in the winter keeps it cool during a heat wave. If the fluid is appropriate and mixed correctly, you have to check to see if the system is full.
Only someone very familiar with cooling systems should check the coolant level at the radiator. The chance of serious injury exists since you are dealing with hot coolant which is pressurized to about 18 psi. If you have any doubts check the reservoir bottle instead for the proper level which is usually marked on the side of the bottle. Be sure to read any labels around the bottle or cap since this vessel could also be pressurized.
Be aware that this is a closed looped system and that coolant is siphoned out of the bottle and into the radiator as needed. The best time is to check the level is when the engine is cold and no pressure is present. It’s best to feel the top radiator hose to see if it is hard, if it is there is still pressure on the system and caution is needed.
If the system is low it should raise concerns if not the first time then after repeated “topping off”. Any need for additional coolant should cause you to check underneath the car for leakage. This could be anywhere under the engine compartment, in the front for a leak in the radiator, in the middle for a water pump, or just about anywhere else if any of coolant hoses were to start to leak. In a heat wave your system must be full otherwise your engine will overheat.
A restricted radiator that prevents the free flow of coolant will cause your car to run hot in a heat wave. It would be difficult to definitively track this down without professional input. However, if your car runs hotter at higher highway speeds it may be a sign that your radiator is restricted.
Air flow is just as important as coolant to a car’s ability to stay cool in a heat wave. Make sure that the radiator or AC condenser is free of any obstructions which would cut down the air flowing through the radiator. Bags or birds have been known to attach themselves to the front of cars causing them to overheat.
Check to see that the cooling fans (on cars with electrically driven fans) are cycling on and off as needed. Running the motor at idle for 10 to 15 minutes usually produces a need for the fan to be engaged, if not take the car out briefly and return to recheck. If your car has a belt driven fan check for air being sucked through the radiator and back over the engine by way of the fan shroud, being careful not to cause yourself harm by coming in contact with the fan itself. Lack of air flow back over the engine could mean you have a bad fan clutch.
Overheating is a major source of engine failure. Running hot happens more often as the outside temperature climbs, but monitoring your car’s coolant and air flow can prevent heat related motor problems.