Tips on What to Do If Your Car Overheats

First there are two things you should never do when your car overheats. 1. Do not try to remove the radiator cap and, 2. do not run cold water on the radiator if the engine is not running. The radiator cap is under pressure and if you try to remove it you could be severely burnt from the coolant (the liquid in the radiator). You could crack the radiator if you run cold water on it without the engine running.

Today's cars rarely overheat, but there are reasons why they will. Always be aware of your lights and gauges on your car's instrument panel and know what each one means. If your temperature gauge starts to inch closer and closer to "H" (hot) then shut your air conditioner off. If your car's temperature gauge continues to creep towards "H", then turn your heater on. If you see steam from under the hood or the oil light comes on, pull over and shut the engine off. (Note: Any time the oil light comes on or the oil pressure gauge drops, pull over, shut the motor off and do not attempt to start the engine until a mechanic has worked on it.)

Steam from under the hood may indicate you have a hole in a radiator hose. Carefully open the hood and look to see where the steam is coming from. Do not stick you face or anything else in the steam. You could get burnt doing this. A small leak in a hose can be repaired with radiator hose tape, but do not attempt this until the motor has cooled down. Also, the hose should be replaced as soon as possible.

Getting to running water is the next best bet. Do not drive more than a quarter mile when the engine is overheated. Have it towed.

It is always best to have an experienced mechanic take care of your vehicle, but if there isn't one handy, there are things you can do. First, if the radiator reservoir is empty, fill it with water. Then, with the motor running, apply water on the radiator. When the engine is running it causes the coolant to flow through the radiator which will keep it from getting too cold too fast when water is applied.

It may take several minutes for the engine temperature to drop to normal. If it doesn't show improvement within a few minutes, it is best to shut the engine off and let it cool on its own. This may take a couple of hours. Then have it checked by a mechanic.

The question is what caused it to overheat? There are several reasons a vehicle will overheat. One of the most common is a broken fan belt. Have the belt replaced.

Another common problem is the lack of coolant. You can add water but you will need antifreeze even if you live in a year-around warm climate. Antifreeze keeps the engine from rusting. The lack of coolant means there is probably something else wrong. Look for leaks in the radiator, heater and radiator hoses. Antifreeze on the floorboard may mean a leak in the heater core. (Note: If you see something leaking from under the car on a hot day and you have been running the AC, this is probably condensation from the AC and not coolant. Hint: Antifreeze is green.)

No leaks? Then pull your oil dipstick and look at the oil. If the oil is brown and looks like mud, the antifreeze is seeping into the engine. This will mean you have a cracked engine block or head, or a blown head gasket. (Note: If the oil isn't brown, you can still have a blown head gasket and the coolant is leaking into the pistons.)

Also have your radiator cap's pressure checked. The cap is designed to hold pressure. Not enough pressure will cause the engine to overheat. Liquid under pressure boils at a higher temperature, therefore keeping it from boiling away. On the other hand too much pressure will cause a crack in the radiator or even blow the radiator top off.

Have the radiator checked under pressure. If there are any leaks a pressure check will show them. Also, if the radiator won't hold pressure and there are no leaks, you have an internal problem, like a blown head gasket.

The thermostat can be stuck closed or partially closed. Any restriction in the flow of coolant will cause the engine to overheat on a hot day.

Make sure there isn't anything in front of the radiator that is blocking the airflow. Air going through the radiator cools the antifreeze. Any restriction of this airflow will cause the motor to overheat on a moderately warm day.

If the engine is overheated and the vehicle is equipped with electric fans, make sure they are running. Electric fans that do not work will cause a vehicle to overheat. (Note: Electric fans will not run if the engine is cold. Both electric fans, if so equipped, will not necessarily run if the motor is below normal temperature. Only one may run at a time. However, if it is overheated, both fans should be running. Caution: If an electric fan is not running, do not stick you fingers or anything else in it. It may start at any time.)

A defective water pump will cause the engine to overheat. A defective water pump will usually leak or make noises. (Note: Just because the pump makes noises does not mean it is defective--but it could be a sign that the pump is going bad.)

If it is the middle of winter and your car overheats and there are no problems mentioned above, the problem may be the freezing point of the coolant is not adequate. It may have froze. Have your car towed to a heated garage and leave it until thawed. Then have it checked by a mechanic for damage.

There are preventive measure you can take to keep your vehicle from overheating. I know in this busy world you don't have time to pop the hood every morning (even though this is one of the best ways to keep from having any car problems). You should check under the hood before starting your car at least once a week. Look for any leaks, bulges or soft spots in the radiator hoses, check the oil, belts for cracks, power steering fluid and the antifreeze in the overflow reservoir. If the reservoir is empty, you can fill it with water but have it checked by a mechanic. If you have an automatic transmission, start the engine and check the transmission fluid. Also, have your antifreeze checked for its freezing point before winter every year and have it replaced every three to five years.

Of course, there are things you won't be able to see such as a thermostat that is going bad, but a visual check may save a lot of headaches down the road--especially if you're planning a trip.

Happy driving!