Engine overheating problems may be a result of a malfunctioning water pump, fan belt, coolant level being too low, poor heat transfer from the engine to the air passing over it, internal hot spots in the engine such as carbon build-up, or excessive blow-by past piston rings or valve seals.
All these conditions can cause the engine’s temperature to rise, which is dangerous if it goes above the designed maximum.
In a typical motor vehicle, heat is removed from the engine by a system of water or air pumps and fluid or “coolant” jackets surrounding the cylinders and other internal parts of the engine. In this way, the energy generated by the combustion process is transferred to the coolant as heat which then dissipates into the surrounding atmosphere.
Table of Contents
The Most Common Causes of Engine Overheating
Following are all the major and minor causes of engine overheating:
- Clogged radiator
- Leaking head gasket
- Clogged air intake
- Lack of engine coolant
- Faulty radiator fan
- Faulty thermostat
- Blocked exhaust
- Faulty coolant temperature sensor
- Blown head gasket
- Faulty water pump
- Clogged coolant hose
- Improper installation of water pump
- Loose Water Pump Sleeve/Journal Bearings
- Loose Thermostat Sleeve/Journal Bearings
- Faulty radiator cap
- Mechanical problems
- Loose/Missing Cooling Fan Blade(s) or Shroud
- Loose/Missing Radiator Shroud Mounting Hardware
- Cooling system flush
- The faulty pressure relief valve
- Loose fuel tank cap
- Clogged radiator core
Let us have a look at these causes in some detail:
1. Clogged Radiator
The cooling system in a car works by circulating coolant through the engine and then to the radiator, where it is cooled before being circulated back to the engine. The car’s coolant pump lubricates and pumps the fluid through this system. If a clog blocks or slows down this process, it will cause the engine to overheat.
A clog in the radiator can cause overheating when you are driving because the coolant travels through only one path when it goes back into the engine. If your car’s cooling system has a leak or another problem, this could also contribute to an overheated engine by causing it to lose fluid.
2. Leaking Head Gasket
The head gasket is the seal between the cylinder head and engine block. If it fails, your car may begin producing blue or white exhaust that smells like anti-freeze. It also will cause an increase in oil consumption and a decrease in power while you drive until, finally, your engine overheats.
3. Clogged Air Intake
An air intake is the ventilation system in your car through which outside air flows. When it is clogged, it can cause overheating by restricting the supply of fresh cooling air to the engine.
4. Lack of Engine Coolant
If you run your car without enough coolant in the coolant reservoir tank, this will cause overheating by restricting the supply of fresh coolant to the engine. You must also ensure that you are not refilling the wrong coolant in your car. Check for any cooling system leak as well.
5. Faulty Radiator Fan
The radiator fan is a component of the car’s cooling system that pulls air across the radiator so that it can cool down and remove heat from your car’s engine. If your radiator fan fails, it will not be able to cool the engine, resulting in overheating.
6. Malfunctioning Thermostat
A thermostat is a device that regulates your car’s temperature by controlling how much coolant circulates through the engine. If it fails, this will cause overheating as well as an increase in fuel consumption and a decrease in power while you drive until finally, your engine overheats.
7. Blocked Exhaust
If the exhaust is obstructed in any way, it will restrict the flow of hot air, which would normally be expelled from the combustion chamber. This will reduce the amount of heat that can escape and contribute to overheating.
8. Faulty Coolant Temperature Sensor
A coolant temperature sensor is a device that tells the car’s computer the engine’s temperature. If it fails, this will cause overheating as well as an increase in fuel consumption and a decrease in power while you drive until finally, your engine overheats.
9. Blown Head Gasket
The head gasket is the seal between the cylinder head and engine block. If it fails, your car may begin producing blue or white exhaust that smells like anti-freeze. It will also cause an increase in oil consumption and a decrease in power while you drive until, finally, your engine overheats.
10. Broken Water Pump
A water pump circulates coolant through the engine and its surrounding components to keep it running at a proper temperature. If the water pump fails, the result is overheating due to a lack of fluid circulation through that part of the system.
11. Clogged Coolant Hose
A clogged hose can restrict coolant flow through the engine and heat-sensitive components around it. This will cause overheating.
12. Improper installation of Water Pump
If there is too much play between the pump and journal bearings inside the engine block, this will lead to overheating in about 2-3 years time when journal bearings start wearing out due to excessive pumping action of the water pump.
13. Lose Water Pump Sleeve/Journal Bearings
If not tightened properly by the factory, this will cause the water pump to lose its pumping action in about 2-3 years when journal bearings inside the engine start wearing out due to excessive movement of the water pump shaft inside of the journal bearings.
14. Loose Thermostat Sleeve/Journal Bearings
If not tightened properly from the factory, this will cause the thermostat to lose its opening and closing action in about 2-3 years when journal bearings inside the engine start wearing out due to excessive movement of the water pump shaft inside of the journal bearings.
15. Faulty Radiator Cap
Radiator cap not letting coolant inside the radiator core at the proper pressure will cause coolant to flow out of overflow tube because oil does not expand when it gets hot, unlike water, causing the pressure inside the radiator core to drop.
16. Mechanical Problems
Overheating due to engine mechanical problems can occur. Worn-out journal bearings in the engine, worn-out piston rings inside a diesel engine, loose connection in the cooling system, etc., will cause car overheating issues.
17. Loose/Missing Cooling Fan Blade(s) or Shroud
A loose/Missing cooling fan blade or shroud can obstruct the coolant flow. The cooling fan needs a free flow of air to cool the radiator core if fan blades are broken off or missing, the fan will overheat due to lack of airflow.
18. Loose/Missing Radiator Shroud Mounting Hardware
Loose/Missing radiator shroud mounting hardware is yet another cause of car overheating. If not appropriately tightened from the factory, this will allow the fan shroud to move excessively due to wind pressure and vibrate the coolant hose away from the radiator heater core, causing a gas or coolant leak.
19. Cooling System Flush
Engine temperature may rise due to cooling system flush. Most car dealers I know of flush the cooling system with tap water after a radiator core is replaced, if tap water is used inside an engine’s aluminum cooling system, it will cause premature corrosion and failure. Engines overheat as a result of this.
20. Faulty Pressure Relief Valve
Pressure Relief Valve not releasing excess pressure from the radiator core will cause the car to overheat. If the radiator cooling fins are damaged on the inside, or if too much oil has been added into the coolant mixture, or the pressure cap is missing or defective on the radiator core, this will cause excess pressure inside of the cooling system and push the coolant out of overflow tube.
21. Loose Fuel Tank Cap
A loose fuel tank cap will result in an overheated car. If the fuel tank cap is not tightened properly from the factory, it will cause the engine to overheat due to pressure build-up in the engine’s cooling system.
22. Clogged Radiator Core
A clogged radiator core requires a repair service appointment. If the aluminum radiator core has become clogged with dirt, scale, rust, or other contaminants, it will start pulling heat. This will increase the operating temperature of the engine.
If an overheated engine is allowed to continue to operate, severe damage or even pre-mature failure may occur due to the expansion of internal parts. If this is ignored, one or more of the following conditions will almost inevitably lead to total engine seizure.
Overheating can also be caused by a loss of coolant or because the water pump has failed. This may be due to a blocked radiator, blown head gasket, or cracks in the engine block.
Black smoke coming from your car’s exhaust could indicate another problem with your car, like poor fuel quality or a vehicle that needs some routine maintenance. However, black smoke coming out of your exhaust could also be caused by overheating due to lack of coolant or because the cooling system no longer has enough pressure to circulate the coolant.
The temperature gauge or warning light is a key indicator that lets us know when an engine is running too hot. In response, the driver must pull over as soon as possible, stop the vehicle, and investigate the cause.
Frequently Asked Questions
How overheating is bad for your engine?
Overheating is bad for your engine because it leads to various problems, which can be anything from too much oil consumption to complete engine failure. The problem is that the sensor used to measure the temperature of the engine block detects just one spot at a time, and you might be driving for a long time or doing a lot of idling before your car begins showing any signs of problems.
How can you solve the problem of car overheating?
You can solve the problem of engine overheating by following these tips:
1. Keep the engine tuned and in good condition. A poorly tuned engine can contribute to overheating.
2. Do not force the engine to work harder than it has to. The harder you make an engine work, the more heat it produces and overheats sooner.
3. Use the recommended engine oil type and viscosity for your vehicle, and keep to the correct level.
4. Check that there is sufficient cooling air passing through the radiator, this may be restricted by a build-up of leaves or insects in the front grill.
5. Regularly check the radiator and hoses for leaks or damage. Make sure the overflow tank is filled to its proper level.