02/12 2008, Tuesday 12:37
Overheating Causes N’ Cures
How hot is too hot? And if the engine is hotter than what is expected, what are you supposed to do?
The answer to those queries could save you from a life threatening auto experience. It’s always great to know the causes and cures so as not to fret and panic. To give a clear premise, here is a brief discussion …
Causes:
Overheating may be caused by anything that decreases the cooling system's aptitude to take in, transfer and disperse heat. Causes include faulty thermostat, low coolant level, coolant leak, poor heat conductivity inside the engine, poor airflow through the radiator, slipping fan clutch, inoperative electric cooling fan, eroded/loose water pump impeller, or defective radiator cap.
Overheating can also cause preignition. Additionally, another consequence of overheating may be a blown head gasket. Be cautious. Be very cautious.
So how about the cures?
Cures:
* Thermostat – Severe overheating can often damage a good thermostat. If the engine has overheated because of another problem, therefore, the thermostat should be tested or replaced before the engine is returned to service.
* Cooling system leaks – Make a careful visual inspection of the entire cooling system, and then Pressure Test the cooling system and radiator cap. A pressure test will reveal internal leaks such as seepage past the head gasket as well as cracks in the head or block. A good system should hold 12 to 15 psi for 15 minutes or more with no loss in pressure. If it leaks pressure, there is an internal coolant leak (most likely a bad head gasket but possibly also a cracked cylinder or engine block).
* Fan – With an electric cooling fan, check to see that the fan cycles on when the engine gets hot and when the air conditioner is on. If the fan fails to come on, check the fan motor wiring connections, relay and temperature sensor. Try jumping the fan directly to the battery. If it runs, the problem is in the wiring, relay or sensor. If it fails to run, the fan motor is bad and needs to be replaced.
* Water pump – Any wobble in the pump shaft or seepage would call for replacement. In some instances, a pump can cause an engine to overheat if the impeller vanes are badly eroded due to corrosion or if the impeller has come loose from the shaft. The wrong pump may also cause an engine to overheat. Some engines with serpentine drive belts require a special water pump that turns in the opposite direction of those used on the same engine with ordinary V-belts.
water pump erosion
* Belts & hoses – Check belt tension and condition. Sometimes a lower radiator hose will collapse under vacuum at high speed and restrict the flow of coolant from the radiator into the engine. This can happen if the reinforcing spring inside the hose is missing or damaged.
If you want a more comprehensive discussion on this matter visit aaa1car.com. More tips here.
The answer to those queries could save you from a life threatening auto experience. It’s always great to know the causes and cures so as not to fret and panic. To give a clear premise, here is a brief discussion …
Causes:
Overheating may be caused by anything that decreases the cooling system's aptitude to take in, transfer and disperse heat. Causes include faulty thermostat, low coolant level, coolant leak, poor heat conductivity inside the engine, poor airflow through the radiator, slipping fan clutch, inoperative electric cooling fan, eroded/loose water pump impeller, or defective radiator cap.
Overheating can also cause preignition. Additionally, another consequence of overheating may be a blown head gasket. Be cautious. Be very cautious.
So how about the cures?
Cures:
* Thermostat – Severe overheating can often damage a good thermostat. If the engine has overheated because of another problem, therefore, the thermostat should be tested or replaced before the engine is returned to service.
* Cooling system leaks – Make a careful visual inspection of the entire cooling system, and then Pressure Test the cooling system and radiator cap. A pressure test will reveal internal leaks such as seepage past the head gasket as well as cracks in the head or block. A good system should hold 12 to 15 psi for 15 minutes or more with no loss in pressure. If it leaks pressure, there is an internal coolant leak (most likely a bad head gasket but possibly also a cracked cylinder or engine block).
* Fan – With an electric cooling fan, check to see that the fan cycles on when the engine gets hot and when the air conditioner is on. If the fan fails to come on, check the fan motor wiring connections, relay and temperature sensor. Try jumping the fan directly to the battery. If it runs, the problem is in the wiring, relay or sensor. If it fails to run, the fan motor is bad and needs to be replaced.
* Water pump – Any wobble in the pump shaft or seepage would call for replacement. In some instances, a pump can cause an engine to overheat if the impeller vanes are badly eroded due to corrosion or if the impeller has come loose from the shaft. The wrong pump may also cause an engine to overheat. Some engines with serpentine drive belts require a special water pump that turns in the opposite direction of those used on the same engine with ordinary V-belts.
water pump erosion
* Belts & hoses – Check belt tension and condition. Sometimes a lower radiator hose will collapse under vacuum at high speed and restrict the flow of coolant from the radiator into the engine. This can happen if the reinforcing spring inside the hose is missing or damaged.
If you want a more comprehensive discussion on this matter visit aaa1car.com. More tips here.
