What causes the engine to overheat? How can I tell if my engine is overheating? What can engine overheating lead to?
Is Your Engine Overheating?
Most engines are designed to operate in a “normal” temperature range of approximately 90° to 104° degrees (195 to 220 degrees Fahrenheit), which is necessary for a relatively constant operating temperature, proper emission control, good fuel economy and performance. Sometimes, however, the engine may heat up due to problems.
The engine’s cooling system contains a 50/50 mix of water and ethylene glycol-based antifreeze. Coolant boils at 104° (225 degrees Fahrenheit) unless pressurized by the radiator cap. A 15 PSI radiator cap raises the boiling point of 50/50 coolant to 129° degrees (265 degrees Fahrenheit). If the mixture of water and antifreeze concentration is increased to 70/30 (recommended maximum), the boiling temperature will increase to 135° degrees (276 degrees Fahrenheit) with a 15 PSI radiator cap. Because the pressure rises, the “degree of boiling” of water also increases. The radiator cap is crucial in boiling coolant and heating the engine.
The engine could overheat if the water temperature is higher than normal.
Engine Overheating: Possible Causes
Anything that reduces the cooling system’s ability to absorb and transport heat can cause overheating. Low coolant level, water loss (internal and external), low thermal conductivity in the engine, faulty thermostat, inoperative cooling fan or fan thermal, defective fan thermal, inoperative fan thermal, poor radiator flow, defective fan thermal, defective fan thermal, defective fan thermal, inoperative radiator fan, crushed lower radiator tube, loose or worn water circulation pump or even a defective radiator cover.
Heat transfer is one of the most fundamental laws in nature. It occurs at all temperatures. It is never the opposite. It is essential to cool the metal by keeping it in contact with a cold liquid. This can only be done by ensuring that the coolant is constantly circulated. If the coolant stops flowing due to a leak in the thermostat or water pump, temperatures will rise and cause engine overheating.
The coolant must also be able to remove the heat that is entering the engine. The engine will heat up if the coolant is not able to remove the heat from the engine. If the cooling fan does not spin or move fast enough to draw heat from the radiator, the same thing will occur.
To maintain the engine’s average temperature within the normal range, the thermostat must be in operation. If the thermostat is not opened, it will block the coolant flow and cause the engine to overheat.
Exhaust restrictions may also lead to engine overheating. The engine’s exhaust heats a lot. The exhaust system can heat up inside an engine if it is not properly designed or if a pipe is bent.
It could be that your engine has not warmed up properly, or that your temperature sensor is not working correctly. A lack of coolant can also cause this. The sensor can malfunction if there is too much air inside.
What happens if your engine overheats?
The engine explodes when it is overheated. Engines can explode from excessive jolts and power loss.
Overheating can lead to piston wear. Overheating can cause pistons expand and swell. Due to their limited space, they can rub against cylinders, leading to costly repairs that are not possible.
Exhaust valve can rub or stick to their guides. This can cause damage, jamming of the guides, and loss in compression.
A swollen head gasket in the cylinder resulting from engine overheating can also be a result. The gasket will inflate three times faster than the aluminum cast iron when exposed to extreme heat. The gasket can be inflated by thermal stress, which can cause it to warp or crush. This stops the gasket from performing its task and causes engine water and oil mixtures to occur.
The camshaft can also be damaged by engine overheating.
Engine overheating can also cause strain to old radiator and heater tubes, which could result in them burst due to additional pressure. Radiator damage can also be caused by steam from the cooling system.
It is important to never ignore the temperature warning lamps. Some high-tech cars like the Northstar-powered Cadillac can disable the cooling cylinders in the event that coolant is lost and still operate at low power. However, most engines will experience severe damage if they heat up. If you notice that your engine is heating up, it’s best to stop driving immediately. You should stop the engine and let it cool. Then, you can try to fix the problem before you travel any further.
Check the parts
Thermostat
Overheating can often cause a thermostat to stop working. If your engine has overheated because of another problem, you should have the thermostat tested and replaced.
To check the thermostat, start the engine and check the radiator hose manually. Or use an infrared thermometer to measure its temperature. The thermostat will open when the hose is cold. If the hose gets hot, the thermostat is open.
Another method to check the thermostat is to take it out and place it in a saucepan of boiling water. The thermostat should turn on. A thermometer can be used to determine the exact temperature at which it opens.
You must replace the thermostat with one that has the same temperature rating. The thermostats required for cars and light trucks built after 1971 are rated at 88 or 92.2 degrees. A thermostat set at 71 degrees or 82 degrees is best because it can overheat. Older vehicles equipped with computerized engine control can have major performance issues and emissions problems if the thermostat is not correct.
Important note:
When refilling the cooling systems, air can get trapped under thermostats. This can lead to a vapor layer under the thermostat that blocks the thermostat from opening. If this happens, it can cause the engine overheat. Some refrigeration systems include one or more air purge devices. If your cooling system doesn’t have an air vent valve you can drill small holes as shown in this thermostat. This will allow any air trapped within the engine block to flow through the thermostat. A “sway valve” is a feature found on some thermostats. The thermostat features a tiny hole with a pin that allows air escape.
Cooling System Leaks
Engine overheating is most commonly caused by coolant loss from leaks. Potential leak points include radiator, heater core and water pump.
It is important to inspect the whole cooling system carefully. “pressure test” To inspect the cooling system, and the radiator cap. Checking pressure can reveal internal leaks due to cracks in the block, cylinder seals and block. Good systems should maintain 12 to 15 PSI pressure for 15 minutes, or more, without any loss. If pressure drops, it is most likely an internal leak in your engine.
It is crucial to pressure test your radiator cap. A weak cap (with a low pressure rating) can lower the boiling point and allow the coolant escape from the radiator.
Cylinder head gasket
It is costly to repair a leaking cylinder head gasket. Leakage in the cylinder head gasket can allow engine water to seep into either the crankcase or the cylinders. The most noticeable sign is the white smoke coming from the vehicle’s exhaust. This is especially noticeable if the vehicle has been stopped and then restarted. You can test the integrity of the cylinder head gasket by applying pressure. You can also have a CO2 test. This test uses blue liquid. The liquid is placed in a bag and put in the radiator. The chemical reaction that causes the blue to turn green when there is an engine leak will cause the blue color to change into green.
You can temporarily seal a leaky head gasket by applying a sealant in the cooling system. The gasket must be replaced if there are excessive leaks, or if sealant is not effective.
Fan
Most motor overheating problems with mechanical fans are caused by a bad fan thermal. A missing fan shroud, depending on how far the fan is from the radiator, can cause a fan to lose up to 50% of its cooling efficiency. This can lead to engine overheating, especially in hot conditions or when the engine is overworked.
Overheating problems can be caused by faulty fan thermal. The radiator cooling fan is mechanically activated by the fan thermal. This thermal adjusts the temperature to allow the cooling fan run at maximum power. It slowly deteriorates and loses about 200 rpm each year. Due to high temperatures, fan thermals can sometimes become damaged over long periods of time. If the fan thermal stops working, the cooling system can’t function properly and the engine will overheat. It is possible to purchase a new fan heater in this situation. A fan thermal has a life expectancy of approximately the same length as a water pump. If one of them is broken, the other must be repaired.
If the fan thermal shows signs of fluid leakage (oily lines radiating from the hub), or if the engine spins quickly with little resistance when turned on, or if the fan wobbles when pushing the fan in, the fan needs to be replaced.
Hydraulic cooling fans must be spun fast enough to provide sufficient cooling both at idle speed and at low speeds.
Water Pump (Recirculation).
Any wobble on the shaft of the pump is an indication that it should be replaced. Sometimes the propeller blades may become worn from corrosion, or the propeller could come loose from its shaft. This could cause the engine’s temperature to rise. Motor overheating can also be caused by the wrong pump selection. Special water pumps are required for engines with serpentine drive belts. They rotate in a different direction than regular V-belts.
Water pump impellers can sometimes become loose on the shaft of the pump. This causes the water pump pulley to not turn, even though it seems to be spinning normal. If the impeller is not turning, it could be that there is insufficient or no coolant circulation. You can only determine if the problem exists by removing the water pump and checking the impeller. Plastic wheels can also wear out over time. Cavitation erosion may also occur in the impeller and water pump body. Increased clearance between the impeller and the housing will decrease coolant flow and increase engine heat.
Strap
Make sure to check the belt’s condition and tension. Untightened belts can cause the water pump to not circulate coolant quickly enough, and/or the fan to stop turning fast enough for proper cooling.
Lower Radiator Hose
The engine can overheat if the hose is pinched or crushed (upper or lower). A large spring-like metal reinforcement wire is usually found inside the lower hose. This wire is there to keep the hose’s integrity as the water pump draws water. The hose could collapse if this wire is damaged or missing.
Filled or dirty radiator
The radiator can become blocked by dirt, insects, and debris that reduces its ability to heat dissipate heat. Coolant flow can be blocked by internal corrosion or deposits. The best way to identify internal blockages is by scanning the radiator with an Infrared thermometer. To clean a clogged radiator, it must be removed and replaced. Although chemical cleaners and flushing the cooling system will remove rust deposits, they won’t be enough to clear a blocked radiator.
After filling up the cooling system, don’t forget to empty the inside.
Excessive Exhaust Back Pressure
Clogged catalytic converters can restrict exhaust flow and cause increased heat buildup in the engine. A crushed exhaust pipe, or a collapsed double-walled pipe are other causes. You should check the idle vacuum. If the intake vacuum readings are low or continue to fall, it is time to check the exhaust system.
Brakes
Your engine may run harder if the parking brake or disc brake caliper is stuck. The engine could overheat in this situation. If necessary, check the brakes and make adjustments.
Engine Overwork
Many passenger cars have very poor cooling systems. It doesn’t have the capacity to cool heat generated by hot weather, high speed mountain driving, and long-term use. The cooling capacity can be increased by replacing the radiator with one that is thicker or larger.
