While there are some vehicle issues that you may be able to drive with for a long time, one problem that you can’t drive with for long is an engine that is overheating.
Driving with an engine that’s overheating will very quickly result in a one-way trip for your engine to the junk yard. This is why you want to identify and resolve any possible engine overheating problems before you get behind the wheel.
In this article, I am going to discuss the things that can cause a vehicle to overheat while driving and some solutions to the problem. I will also explain how to diagnose overheating engines.
By the end of this article, you will have a good idea of some possible causes of car overheating and the best solutions available. But first let’s take an in-depth look at the reasons why a vehicle’s engine can overheat.
10 Common Causes of Car Overheating
The most common reasons for a car engine overheating are low engine coolant, a faulty thermostat, coolant leaks, radiator problems, a failing water pump, and a lousy engine cooling fan.
However, there are other possible causes, such as air pockets in the coolant, low coolant pressure, and low engine oil.
Let’s look at these possible engine overheating causes one after the other for a clear understanding of how they affect the engine temperature.
#1. Low or No Engine Coolant.
Engine coolant is primarily meant to extract heat from an engine. If engine coolant is low or non existent, it creates the opposite affect.
The engine would have a greater temperature variance due to overheating effects from ether boiler effect or open system state of heat via air to engine heat transfer. If you find that your engine coolant is low regularly, you should find out where the coolant is going.
However, there is an acceptable loss of engine coolant. That is, over time and without your knowledge, there could be a slow metric deviation with engine coolant levels – just not an unstable output.
#2. Bad Thermostat.
The thermostat’s role is to allow engine coolant from the radiator in to the engine. While engine coolant is still cool, the thermostat is closed.
When the engine coolant reaches average operating temperature, the thermostat opens to allow engine coolant in.
As indicated, the role of the thermostat is to help the engine reach its average operating temperature and to eliminate engine overheating. If the thermostat is stuck in the closed position, the engine will overheat.
#3. Bad Water Pump.
When the thermostat calls for coolant to exit the radiator into the engine, the water pump circulates the engine coolant into the engine to those areas that need it.
If it fails as a part, the engine coolant will stay in one area within the engine, and lead to that area overheating which will ultimately lead to engine overheating. Its still important to indicate is that a bad water won’t fail readily.
#4. Coolant leaks.
Coolant leaks can be an internal leak or external leak. External leaks happen when the coolant is leaking out of the system and internal leaks occur when the coolant leaks into other parts of the engine or something leaks into the coolant.
For instance, oil in coolant and coolant in oil are examples of internal leaks. If the coolant has oil in it, it will not cool the engine like it should until you find and fix the problem. With external leaks, this will either be low or no coolant in the radiator.
#5. Damaged or clogged radiator.
The radiator sends cool coolant to the engine and receives hot from the engine. The hot coolant will flow through the radiator fins when it enters the radiator, cooling it before sending it back to the engine.
If the radiator fins are damaged or clogged, it will not be able to cool the hot coolant before sending it back to the engine. This will causes the engine to inevitably overheat.
#6. Damage engine coolant fan.
The engine coolant fan blows a breeze on the radiator cooler fins to help dissipate the heat from the hot coolant that is running through it, and is more important when the car is idling. So if your car only overheating when idling, then you have a damaged coolant fan.
#7. Defective temperature sensor.
An electric coolant fan is only working in harmony with the temp sensor.08. Temperature sensor.
The sensor provides power to the fan when the engine reaches a specific temperature, which helps the engine maintain an optimal temperature. If the temp sensor fails, it will not provide the electric flow to power the fan causing the engine to overheat.
#8. Air pockets.
Flushing your engine coolant is vital, but even more so is ensuring there are no air pockets in the system.
Air pockets have been known to jam the entire cooling system, preventing all coolant flow. Therefore, it is essential to follow the flushing instructions in your owner’s booklet. Air can enter the system through a defective radiator cap or blown head gasket.
#9. Low engine oil.
Low engine coolant is another contributory cause of engine overheating. Oh yes! Read that again. Engine oil does not only lubricate the internal reciprocating engine parts, it cools the engine too.
Without motor oil, there will be too much friction in the engine causing the temperature to rise. If the engine temperature rises too high, the engine will overheat. It is uncommon to see overheating due to low engine oil.
#10. Bad hoses or bad belts.
If you can trace engine overheating it could boil down to coolant full to bad horse or drive belts. The drive belts and hoses are very important to the cooling system, air conditioning system, and the charging system.
The drive belt transfers engine output power to the alternator, cooling fan, power steering pump, and compressor while the heater core and radiator hoses transfer engine coolant to and from the engine, heater core, and radiator.
If the drive belt connecting to the water pump and engine fan is bad or is faulty radiator hoses, engine overheating will occur.
What should you do if your Car Engine Overheating?
Your car is overheating, now what? Here are temporary repairs for overheating cars. These will help you avoid damaging the engine.
- Shut off the air conditioner. This will relieve some extra stress on the engine.
- Turn on the car heater. Yes! The heater. The heater will help to reduce the overheating because it will take some heat away from the engine.
- Find a safe place, and pull over. Turn off the vehicle.
- Let the engine sit for 30 minutes to cool off.
- Look if your radiator fluid is gauged. If not, fill it to the proper type of fluid needs.
- Look to see if you have any coolant leaking and that the fan is coming on.
- You may want to drive down to a repair shop, while watching the dash.
Effects of an overheating engine
Engine overheating is the fastest way to harm your engine. Extreme engine overheating can result in engine parts like pistons and cylinders warping, distorting, or bending.
It breaks down seals between the engine and the cylinder walls that stops oil from creeping into the combustion chamber and burning with your fuel.
Warped pistons/cylinder walls will also create grinding, whining, knocking, and other awful noise from your engine. Engine performance will significantly decline. In the worst case scenario, the warped pistons will break causing engine seizure.
How to Diagnose Overheating Engine
Different types of engine overheating have different steps to diagnose an overheating engine.
Step 1: Inspect the radiator cap and coolant level
Park the vehicle on a leveled surface and allow the engine to cool for at least 30 minutes. Remove the radiator cap and visually inspect the coolant level.
The coolant should be all the way to the top of the radiator cap, If not, fill the system with coolant fluid to fill the level.
Inspect the radiator cap for rust, corrosion, or visible damage. If the radiator cap is defective, replace it. If you discover any issues besides the coolant level during this step, fix those as well.
Fill the vehicle up and then trip it after you repair an issue. If you restore it after you repaired two or more issues, you will not know which issue was the cause.
Step 2: Check for cooler leaks
Now that the radiator has been filled, turn on the vehicle, and now check for leaks, especially of Draining Coolant from Everywhere.
This leak maybe officer. If you notice a leak of coolant from any place, trace this back to its origin. Cool your cooling system, then inspect all components concerning the cooling system. The leak can come from more than one source.
Step 3: Check the engine fan
While the engine is running, check to see if the coolant fan is spinning. On some vehicles, you may not see the fan rotate until the engine reaches an average operating temperature.
Before doing this check again, make sure you turn off all climate controls as well. Sometimes, by turning on all climate controls you bypass the relay trigger, which is what we are checking when you turn on the engine.
Now, check to see if the fan starts spinning. If you find the fan does not come up and the engine starts overheating, it means you either have a broken fan or a failed relay that controls the fan.
To narrow this down to see if you have a failed fan or failed relay. Get two wires, and on each end, connect these two wires to the 2 pins on the fan.
On the other ends of the wires connect to the positive and negative battery terminals. If the fan spins, the fan is good, if it turns then you have a failed relay. If it doesn’t turn, you have a broken cooling fan.
Step 4: Inspect drive belt
Sometimes the drive belt can snap off, and you may not even know if this happened or not, but you should check one last time the belt is there.
If the belt that turns the water pump is broken, the pump cannot circulate the coolant into the engine parts. Which do to volume will cause the engine to overheat more than you think.
If the belt is present, inspect and check if the belt is tight. If the belt is loose, then the tension should be adjusted through the belt adjuster.
Step 5: Burp the cooling system
If air has pockets in the radiator, the only real fix is to burp the cooling system. You will need the recommended coolant for your vehicle, and a spill free funnel.
Attach the spill-free funnel to the radiator filler opening. Next, start your car, and allow the air bubbles to rise out of the radiator.
The funnel will come with several different attachments. Be sure to read and follow the direction given to you in the manual instructions.
How do you fix a car engine that gets overheated?
After diagnosing the car, you need to do one or several of the following to repair an overheating vehicle’s engine.
- Top-Up the engine coolant.
- Repair the coolant leak.
- Replace the broken radiator fan.
- Replace bad thermostat.
- Flush the engine coolant.
- Unclog the radiator.
- Replace broken water pump.
- Replace damaged temperature sensor.
- Burp the radiator.
- Change blown head gasket.
But in actuality, can an engine survive overheating? The answer is yes. if you notice and repair the engine overheating at the early stage it will not do too much damage to your car engine!
How do you Avoid unexpected Car overheating?
Prevention is better than cure. Usually, it is better to be proactive than retroactive. Follow my proactive tips to prevent your car from overheating.
- Never forget to check the coolant level and top it when necessary.
- Take the time to check the drive belts, hoses, and cooling fan occasionally.
- Make sure to flush the radiator out on an occasional basis.
- Always monitor the gauges on your dashboard while driving.
- Take your car in for regular maintenance.
How much does it cost to fix an overheated car Engine?
The price of fixing engine overheating could simply be $20 or $2,000. If the problem is that your engine has low coolant you can get the coolant for $20, if the issue is a blown head gasket, you will be paying in the range of $2,000 for repairs.
With so many potential engine overheating issues, it is hard to give an exact repair price. Besides the main culprit of the overheating, how much your vehicle will cost to repair also depends on the makes and model of your car.
Final Words
Car overheating is one of the worst engine problems that you shouldn’t take lightly. Most of the time, car overheating causes are as simple as a coolant leak from a hose that has come loose, or simply low engine coolant.
If you leave it alone for too long, you could cause catastrophic damages, and expensive repair bills.
For that reason, always pull over to a safe location as soon as you notice the temperature gauge rising on the dashboard. Then, use the recommendations above for what to do if your engine overheats.