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