Engine Overheating Causes and Possible Solutions

When considering various causes of engine overheating, your car may be at great risk. The sudden hike in temperature, causing the big red to show, may seem pretty disastrous for your vehicle. Nevertheless, I would be revealing some engine overheating causes and tips on how to fix such issues.

You may soon find the engine parts start having a “seize” effect and other common engine problems. In most cases, engine overheating due to a faulty cooling system may worsen if not fixed quickly. With such, the heat gets trapped without possible means of escaping.

Soon, your car may start emitting steam, and you can start perceiving that “burnt” smell from the vehicle’s engine area. Good care for the car engine would also help prevent engine overheating. Suppose, your engine starts overheating, you should try to find the cause and fix it quickly.

Engine Overheating Causes

Knowing the cause of the engine overheating can help you fix that issue in no time. There are various reasons why your car’s engine is overheating. Some common factors include:

engine overheating signs

Faulty Thermostat

Why is my car overheating? Well, that could be due to a faulty thermostat, and a quick repair would help. The main valve in your car’s cooling system is the thermostat. It works effectively in allowing a smooth passage of the coolant to the radiator when the need arises.

Nevertheless, some issue arises when the thermostat appears stuck in a closed position. With that, the coolant would face some difficulties passing through. In extreme cases, the coolant would not pass through to the car’s engine.

So, when you notice your vehicle’s engine overheating, it would be beneficial to check the thermostat. You may need to seek expert assistance to get the car checked and seek possible solutions to avoid bigger issues.

Head Gasket Failure

One of the major car overheating causes is a faulty head gasket. This part of the vehicle is situated between the cylinder head and the engine block. It works effectively in sealing the coolant chambers, as it also expands thermally alongside the car’s engine.

With the head gasket blown, leakage and the fluid can easily enter the combustion chamber. Hence, the coolant may slowly seep through into the car’s oil system and form a sludge beneath the oil cap.

The loss of fluid from the car’s cooling system would often reduce the level of heat that leaves the engine to the coolant. In essence, this could be the cause of your engine suddenly overheating, and you should try to get your car checked.

Bad Radiator

The radiator is the part that lets in the coolant, where it “cools back.” In essence, when the radiator faces some damage, the coolant may appear warm. A bad radiator in a car can result from leaks and clogging, and such disruption can cause the engine to overheat.

Worn Out Hoses

Again, there may soon be sediments with built-up insulating layers present around the coolant hosing. Such issues may be due to electrolysis in the radiator, and the hose may soon start degrading the hose.

With the number of heat cycles that they’ve passed through, the tube may start cracking. When the radiator hose starts wearing out, there may be leakages. This condition further results in engine overheating.

Ill-functioning Radiator Fan

Various car models come equipped with radiator fans that help them remain and operate at optimum temperature. Interestingly, you find them close to the car’s radiator. They work well in keeping the engine’s temperature low and preventing overheating.

These radiator fans pull air and pass them through their fins, and a bad radiator fan can put an end to such helpful activity. Once the car’s fan motor gets broken, there would be no help reducing the engine’s temperature. Hence, the noticeable overheating suddenly occurs.

Coolant Leak or bad Coolant

There are high chances of the coolant leaking if the head gasket, thermostat, radiator, water pump, and hoses get damaged. With the leak, your engine would start overheating; and you need to fix it as soon as possible.

Why is my car overheating, but it has coolant in it? Supposing there is no coolant leakage, the engine overheating may result from a bad coolant. Perhaps you newly replaced the coolant, and you mistakenly used the wrong fluid, the engine would still overheat. Thus, you’d need to flush the system and refill it with the appropriate fluid.

Low Oil Level

Undoubtedly, oil in vehicles’ engines works effectively as a lubricant and ensures the smooth running of the moving parts. However, the oil acts as a lubricant and can also help control the engine temperature. Simply put, when the oil level decreases, there may be a swift increase in the engine temperature.

Issues with the Radiator Cap

Most folks forget about their car’s radiator cap when they start noticing overheating. Still, it remains one of the causes of engine overheating. With a bad radiator cap, there may be a loss of coolant and engine overheating. Thus, there is a need for you to check the radiator cap and replace them when faulty.

With these causes of engine overheating mentioned above, some possible repairs would include:

  • Conducting a suitable coolant flush
  • Replacing the cracked or damaged coolant hose
  • Getting the water pump replaced
  • Replacing or merely repairing the radiator
  • Replacing the faulty thermostat in the car.

how to diagnose overheating engine

What are the Symptoms of Engine Overheating?

How to diagnose overheating engines? Knowing the common causes of engine overheating will help you learn about the symptoms to enable you to take quick actions and don’t open the car’s hood.

In most cases, the pressure caused by the excess heat can cause some incidents if the hood gets opened too quickly. It is better to let the engine cool for a while after checking the cooling system. Some common symptoms of an overheating engine include:

Notice from the Temperature Light/Gauge

You would often notice the warning light or temperature gauge due to temperature changes. Whenever your vehicle starts exceeding the optimum temperature required for a smooth operation, you can see the temperature light coming on.

The red on the temperature gauge can also  If you don’t find the red indication, you may see the gauge towards the top of its full travel. However, this sign may seem tricky to read, especially when there is a coolant leak.

The “Tick” Noise from the Engine

Without that “thick” engine oil working through the car’s moving parts, it becomes pretty challenging for these parts to move. The oil is a lubricant, and it soon loses its ability when the engine becomes super-heated.

The heat makes the weight of the oil reduce, making it appear too thin like water. Thus, all the lubricating capabilities get lost. With this, the clearances in the engine would start giving off a ticking sound.

The Thumping Sound

A thumping sound often results from a faulty thermostat, blocking the coolant flow to the radiator. Don’t get this wrong; the thermostat often blocks the coolant from flowing to the radiator in a cold condition, as an engine will not start when running cold.

When there’s a failure in allowing the coolant into the radiator, the coolant gets heated within the engine block. When this occurs, you will start hearing this thumping sound from the front area of the engine. It occurs in a bid of the cold coolant situated in the radiator, trying to create a mixture with the heated coolant held back in the engine block.

Steam Emission from the Hood

With the effect of extreme temperature, steam starts emitting from the car’s hood as the coolant starts boiling. In essence, this coolant is way past its boiling point and would start acting like steam water. This sign seems more pronounced, and with it, you can tell that your engine is overheating.

Coolant Spillage

Ever seen a car that has some spillage on the ground after parking for a while? Sometimes it may be fuel or oil spillages. Nevertheless, the coolant may also leak. You can notice such on the ground after parking your car for a while.

Such spillage on the ground can be due to a leak from the cooling system, which would cause the engine to overheat. However, suppose the coolant has been boiling inside the cooling system. In that case, the car finds a way of relieving it through its coolant overflow tank.

Other significant symptoms that you can look out for include a heated hood and poor engine power.

What Happens When An Engine Overheats?

Ever found a driver stranded on the road, watching vehicles emitting smoke. Whether you’ve been in such a situation or not, it can be quite displeasing. Various damages can occur when the engine overheats. The extent of the damage depends on the level of temperature rise. Below are some things that can occur when the engine overheats.

Heat Levels Rising above 20 to 40 Degrees:

With such an increase in temperature above the normal levels, the car may experience engine knocking. There may be a further crack on the piston with continuous driving of a car having an engine knock. The piston ring may soon fall apart, and the electrode strap of a spark plug may soon melt.

Heat Levels Rising above 40 to 80 Degrees:

There would be a serious drop noticeable while driving on this level, and there would be a rattling sound in the engine. Such overheating can even result in the vehicle’s bearing getting damaged. There would also be some damage leading to the engine’s interior surface wearing out and the top piston ring getting damaged.

Heat Levels Rising above 100 Degrees:

Experts in the industry consider this level of temperature increase as a “total meltdown.” The level of damage from this would cause serious damage to the engine. Your car’s engine may never appear the same again, and there may be a need to replace the engine.

Nevertheless, quick action can save some of the vehicle’s components like the engine block, crankshaft, rods, valve springs, and accessory drives. You can also savage the fuel system, ignition system, and intake and exhaust manifolds.

Tips to Prevent a Car from Overheating

The repairs involved in the damages from engine overheating can be pretty expensive. With the various symptoms of engine damage from overheating, it would be best to take some preventive measures. Here are some helpful tips to keep your engine in good condition and prevent it from overheating.

Keep a proper coolant level

One way of preventing engine overheating damage is keeping proper levels of coolant. Thus, it would be pretty helpful to check the levels of the fluids daily. If the fluid levels appear short, you should try to refill them to the right level. With such, you can reduce the chances of your engine overheating.

Refilling with the right coolant

Your gas or diesel engine overheating causes may include the addition of a wrong coolant. Thus, before you refill your coolant, try double-checking the coolant type. It will also help if you take a look at the coolant’s lifespan.

Clearing out the radiator

Due to the debris that may start accumulating in the radiator, the cooling system’s airflow may soon get restricted. Thus, it would be best if you get rid of the sludge by clearing out the radiator.

Take a look at the vehicle’s drive belt

A quick inspection of the car’s drive belt would also prove helpful. If the drive belt gets damaged, there would be serious issues with the coolant circulation. Once you notice the drive belt is damaged, a suitable replacement would be suitable.

A regular maintenance schedule would suffice, ensuring that this problem doesn’t come up. Kindly note that the less thermal stress your car faces, the more effective it would be. Supposing the engine starts overheating while you drive, what should you do?

  • Park your vehicle in a safe area
  • Put off the air conditioner and put down your window glasses
  • Let the car cool for a while and let the pressure reduce
  • Then, open the car’s hood
  • While in traffic, place the car in neutral or quickly rev the engine after parking to help draw some additional fluid and air via the radiator.

Causes of engine overheating YouTube video

Final Words

Various engine overheating causes exist; spillage of the coolant, faulty thermostat, bad radiator and radiator fans, blocked hoses, and broken gasket head. Quick action would be needed to fix these problems and ensure the engine works at optimum temperature.

Again, you can find various symptoms that tell you that the engine is overheating. With that, you can take swift actions that would prevent the engine from getting damaged. Nevertheless, it would help if you prevent the engine of your vehicle from overheating. You can check the excellent tips in this article that proves helpful in preventing engine overheating.


Hi there, I am R. Hasan Tito, a mechanic, and owner of this website. My friend and I created this website to share our knowledge, expertise, and experience with our fellow mechanics' community and car users. I am a specialist and certified automotive mechanic (Both Heavy Commercial and Private Cars). I worked as a Mechanic and Mechanic Supervisor for over fifteen years at Global Rebound Automotive companies - Toyota, TATA, BMW, Nissan, TVs, and Others. Now, I enjoy my new role of leading a team of automotive experts (in their respective fields) and publish new content on a regular basis on my website and social media.

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