The cooling system on a vehicle is probably the most misunderstood part and one of the least serviced. And yet it is probably one of the most important.

If a vehicle doesn't run cool, it won't run at all.According to Tom Kenney, of Tom's Repair, the cooling system is especially important to modern car and truck owners.

"Modern cars are set to run at hotter temperatures than ever before, and they need to run within a certain range or they won't run properly. Computers are set up to take the temperature of the engine into account, and if it's not right then the car won't run right," he said.

He suggested that owners check the system and offered these tips: - Look for any external leaks. Usual areas of leakage are water manifolds, radiator seams, water pumps, freeze plugs and all hose connections.

- Check for internal leaks. Pull the oil dipstick and check for evidence of coolant in the oil.

- Check for a restriction of flow that would cause the coolant not to flow properly.

- Check the fan to make sure it is operating properly.

- Look for restrictions in the air conditioning condenser in front of the radiator.

- Check the radiator cap.

- Check the drive belts.

- Check the thermostat. Besides not controlling the temperature of the engine, it may not be controlling the temperature of the heater.

- Look for internal plugging in the radiator that would restrict the flow of coolant.

- Make sure all belts and hoses are in good shape.

- Make sure you have the proper mixture of antifreeze and water, or a 50-50 mix of the two. The more antifreeze there is to water, the less efficient is the cooling. Antifreeze itself does not have good cooling qualities.

Another part of the cooling systems that few people are not aware of is the oil. It is there to cool the working parts of the engine,. the pistons, crankshaft, cam shaft, cylinders. If the oil is old and/or dirty, it will not do a proper job and the engine will run hotter.

Even the engine should be cleaned off before winter. The engine block radiates heat. If its dirty, then it can't get rid of the heat efficiently.