| The purpose of the engine's cooling system is | | | | Auto Insight program which you can buy online |
| to remove excess heat from the engine, to | | | | from |
| keep the engine operating at its most | | | | |
| efficient temperature, and to get the engine | | | | Common Problems: |
| up to the correct temperature as soon as | | | | |
| possible after starting. Ideally, the cooling | | | | Let's look at the common problems cars have |
| system keeps the engine running at its most | | | | with the cooling system. |
| efficient temperature no matter what the | | | | |
| operating conditions are. | | | | ·Broken hose. Hoses wear out and can leak. |
| | | | Once the coolant has left the system it can |
| As fuel is burned in the engine, about | | | | no longer cool the engine and it overheats. |
| one-third of the energy in the fuel is | | | | |
| converted into power. Another third goes out | | | | ·Broken fan belt. The water pump is driven |
| the exhaust pipe unused, and the remaining | | | | by the engine through a belt. If the belt |
| third becomes heat energy. | | | | breaks the water pump can not turn and |
| | | | coolant will not be circulated through the |
| A cooling system of some kind is necessary in | | | | engine. This will also lead to engine |
| any internal combustion engine. If no cooling | | | | overheating. |
| system were provided, parts would melt from | | | | |
| the heat of the burning fuel, and the pistons | | | | ·Faulty radiator cap. The radiator cap is |
| would expand so much they could not move in | | | | designed to hold a certain pressure in the |
| the cylinders (called "seize"). | | | | coolant system. Most caps hold 8 - 12 PSI. |
| | | | This pressure raises the point in which the |
| The cooling system of a water-cooled engine | | | | coolant will boil and maintains a stable |
| consists of: the engine's water jacket, a | | | | system. If your cap does not hold pressure, |
| thermostat, a water pump, a radiator and | | | | then the car could overheat on hot days since |
| radiator cap, a cooling fan (electric or | | | | the system never becomes pressurized. |
| belt-driven), hoses, the heater core, and | | | | |
| usually an expansion (overflow) tank. | | | | ·Water pump failure. Most commonly you |
| | | | will hear a screeching noise and will be able |
| Fuel burning engines produce enormous amounts | | | | to see coolant leaking from the front of the |
| of heat; temperatures can reach up to 4,000 | | | | pump or under the car. Early signs are small |
| degrees F when the air-fuel mixture burns. | | | | spots of coolant under the car after being |
| However, normal operating temperature is | | | | parked overnight and a strong coolant odor |
| about 2,000 degrees F. The cooling system | | | | while driving. |
| removes about one-third of the heat produced | | | | |
| in the combustion chamber. | | | | ·Head gasket... have large amounts of |
| | | | white smoke flowing out of your exhaust? |
| The exhaust system takes away much of the | | | | Could be a head gasket. The head gasket seals |
| heat, but parts of the engine, such as the | | | | the cylinder head to the engine block and |
| cylinder walls, pistons, and cylinder head, | | | | also seals the coolant passages. When this |
| absorb large amounts of the heat. If a part | | | | gasket fails coolant can enter the cylinder |
| of the engine gets too hot, the oil film | | | | and it will be turned to vapor as the engine |
| fails to protect it. This lack of lubrication | | | | fires. Head gaskets most often fail after the |
| can ruin the engine. | | | | engine has experienced an overheating |
| | | | situation. When super hot, the cylinder head |
| On the other hand, if an engine runs at too | | | | can warp and allow the gasket to fail. |
| low a temperature, it is inefficient, the oil | | | | |
| gets dirty (adding wear and subtracting | | | | Preventive Maintenance: |
| horsepower), deposits form, and fuel mileage | | | | |
| is poor-- not to mention exhaust emissions! | | | | ·Check all belts and hoses regularly. (at |
| For these reasons, the cooling system is | | | | oil change is a good time) |
| designed to stay out of the action until the | | | | |
| engine is warmed up. | | | | ·Look out for coolant leaks underneath the |
| | | | car, they could be signs of trouble to come. |
| There are two types of cooling systems; | | | | |
| liquid cooling and air cooling. Most auto | | | | ·Change your coolant every 2 - 3 years |
| engines are cooled by the liquid type; air | | | | depending on the manufactorers |
| cooling is used more frequently for | | | | recommendations. |
| airplanes, motorcycles and lawnmowers. | | | | |
| | | | ·Inspect your radiator cap for |
| Liquid cooled engines have passages for the | | | | deterioration of the rubber seal. Replace if |
| liquid, or coolant, through the cylinder | | | | you think it is worn. $5 - $10 is cheap |
| block and head. The coolant has to have | | | | insurance. |
| indirect contact with such engine parts as | | | | |
| the combustion chamber, the cylinder walls, | | | | ·Have your coolant system flushed every 5 |
| and the valve seats and guides. Running | | | | years. It gets all the corrosion which has |
| through the passages in the engine heats the | | | | built up out of the system. |
| coolant (it absorbs the heat from the engine | | | | |
| parts), and going through the radiator cools | | | | What to discuss with your mechanic: |
| it. After getting "cool" again in the | | | | |
| radiator, the coolant comes back through the | | | | ·Let your mechanic know when your |
| engine. This business continues as long as | | | | overheating problems occur. Overheating when |
| the engine is running, with the coolant | | | | idling points to a different problem than |
| absorbing and removing the engine's heat, and | | | | overheating at highway speeds. |
| the radiator cooling the coolant. | | | | |
| | | | ·Ask your mechanic if it's worth changing |
| A cooling system pressure tester is used to | | | | the timing belt or chain while he is |
| check the pressure in the cooling system, | | | | replacing your water pump. Many times the |
| which allows the mechanic to determine if the | | | | timing belt turns the water pump so it has to |
| system has any slow leaks. The leak can then | | | | be removed anyway to access the water pump. |
| be found and fixed before it causes a major | | | | |
| problem. | | | | WARNING: Never open your radiator when the |
| | | | engine is hot. The pressure in the system can |
| The above information is directly from the | | | | cause hot coolant to splash out and burn you. |