How to Cool an Overheated Engine?

Engine overheating is a common problem that drivers face from time to time, leading to expensive repairs if not fixed on time. Hence, it is essential you know how to cool an overheated engine. Whenever you experience car overheating, your quick response plays a significant role. It can prevent the issues from escalating to other system components.

Unless you’re a petrolhead or a DIYer, you probably don’t know how to cool down a car engine quickly, so here’s an overview of what you should do when your engine is overheating.

It is crucial to act fast the moment you notice your vehicle is overheating. First thing first, switch off the air conditioning system and turn on the heater and leave it on full blast settings. This will export the heat in the engine bay to the cabin while allowing the engine to cool down fast.

Suppose this proves abortive, or there’s too much steam coming from the engine compartment; pull off the road, open the hood and allow the vehicle to cool. Once the engine is cool, check the coolant level and add some antifreeze if needed.

This is just an overview of what you should do, but don’t worry; this article provides a step-by-step guide to cool down an overheating engine.

how to cool down a car engine quickly

How to cool an overheated engine: Best Methods

There are several causes of engine overheating. Whether you have engine overheating but coolant full or the overheat arises due to coolant leak, we’ll guide you on how to fix it and get back on the road.

Before dealing with how to cool engine overheat, there are symptoms of engine damages from overheating that you should watch out for. They include;

  • Steaming from the hood
  • Temperature warning light
  • Poor engine performance
  • Ticking noise as a result of coolant and engine oil mixture.
  • Thumping noise coming along with superheated coolant.

Now that we have seen the symptoms of engine damages, how do we handle it? Cooling and preventing engine overheating damages involves the following steps;

Do not panic. And, pull out of the road

Regardless of how severe engine overheating may be, it will not cause immediate catastrophic damages. If your temperature light appears on the dashboard, the temperature goes up, or you see steam coming from the hood, don’t panic but carefully pull out of the road.

In any case, do not confuse white clouds from the engine compartment as white smoke. It is steam from the engine, not smoke. So you should carefully pull in a safe place. Switch off the Ac, roll down the windows, turn on the heater to full blast settings to draw all the heat from the engine to the cabin. Switch on the hazard lights while looking for a safe place to park.

Raise the hood

Pop the hood all the way to allow ambient air to get into the engine compartment. However, if the steam is still coming and the hood is too hot to touch, allow it to cool before opening it.

Switch off the engine and leave the ignition on. This will allow the radiator cooling fan and the heater to blow out the heat on the engine bay while the engine stops generating heat.

Allow the engine to cool down before touching any components like the coolant reservoir or radiator cap to avoid splashing hot water on you or burning off your hand.  Now you will be wondering, ‘how long does it take for an engine to cool down completely?’ It takes around 30-45 minutes for an engine to cool down after overheating.

Inspect the upper radiator hose

The easiest way of knowing if the system is pressurized is by squeezing the upper radiator hose that connects the radiator to the engine thermostat. If the hose feels strong when pressed, it indicates the system is still pressurized, and you don’t have to open the radiator or coolant reservoir cap.

In contrast, if the host feels cool when squeezed, it shows the system is cooled and completely safe to open. Ensure you use a clean towel or rag when squeezing the hose.

Do not open the radiator cap

Pressurized radiators will splash hot water on your face. Do not remove the cap until the engine is cooled. That said, you have to play safe and leave the cap if it feels warm.

An overheated engine may have 260°F pressurized coolant. It may not boil while sitting in the radiator, but if opened, it splashes and causes severe injuries.

When the engine is cooled, open the radiator cap with a thick towel or rag. This will grant you access to check your coolant level.

Check the coolant level and leaks

When the engine cools down (which usually takes around 30-45 minutes), check the coolant level in the reservoir tank. The reservoir tank is designed with a white plastic material that resembles a milk jug with a hose that connects it to the radiator.

The reservoir tank has a full and low mark on the body that indicates when the coolant is gauged or not. However, do not confuse normal coolant loss with leaks.

One of the common causes of engine overheat is coolant leaks. If the coolant is low, look for coolant leaks underneath the car, around the thermostat housing, and radiator cap. The cooling system works with pressure. A small leak within the system will cause overheating issues.

Antifreeze has a sweet smell and comes in different colors. If you notice a sweet smell and a red, blue, green, orange, or purple color that flows like water, you have a coolant leak. That said, coolant colors vary depending on your vehicle’s make and model.

Refill the Coolant

If you are asking, ‘can I pour water on my engine to cool it down?’ While it is recommended to top your coolant after overheating due to leaks or low coolant levels, do not pour cold water into a hot radiator. It could lead to cracks on the engine block due to the sudden change of temperature.

It is worth noting that most vehicles require a 50/50 mix of distilled water and antifreeze to function at average operating temperature. If you have coolant, pour it on the radiator and reservoir tank when the engine is cooled.

You can mix the coolant with water since most cars are designed to work with a 50/50 mix. However, some coolant is already mixed, which means you don’t have to remix it.

Suppose you don’t have antifreeze and nowhere to get one at your disposal, fill the radiator and reservoir tank with water, but you shouldn’t allow it to stay for long. Drain the water and replace it with recommended antifreeze when you get to your destination.

Start the car and check the temperature

Turn on the engine and watch the temperature gauge on the instrument cluster rise within a minute or two. If the temperature goes above the standard level, turn off the engine and allow it to cool down within the next 10-15 minutes.

With the radiator cap open and filled with coolant, turn on the engine; if the radiator vomits water when cranking the engine, it indicates you have a blown head gasket that needs replacement. If everything works fine, get back into your ride and continue to your destination until you see a mechanic for a thorough inspection.

Call a tow-van

In a situation, you have a busted hose, coolant in the oil, or a dripping coolant from anywhere around the system, call a tow van to tow your vehicle to a mechanic garage.

Overheating can cause your engine to swell, expand, swap, or crack. A cracked cylinder head can separate from the engine block, resulting in a leak on the gasket cylinder. A leaky cylinder head can cause engine burning oil and coolant.

The good news is, before it gets to this point,  the overheating must have been happening for quite some time. That’s why you shouldn’t allow overheating engines to linger for any reason.

can i pour water on my engine to cool it down

FAQs:

Q: Is an engine ruined if it overheats?

Engine overheating is the thing that damages engines quickly. Engine overheats, if not fixed on time, will cause catastrophic damages to system components, resulting in an expensive repair. A severe overheat can ruin an engine by causing the following;

Blown head gasket: Head gasket is a watertight seal designed to seal the engine block with the cylinder head. It has openings that safely directs coolant to its holes for cooling purposes, keep the motor oil in the oil gallery, and transports gasoline for combustion processes.

An engine can cause the component to swap, expand, swell, or even burn. A burnt head gasket is known as a blown gasket. A burnt cylinder gasket will allow motor oil and coolant to mix, which will affect the smooth running of the engine.

Cracked engine block: Most cylinder heads and engine blocks are made with the same material. Since the cylinder head can warp or swell due to overheating, so can the engine block.

Engine overheat can also cause some parts of the engine block to crack, resulting in coolant in engine oil, major oil leaks, or even total damage to the engine block.

Warped pistons and cylinder walls: Every ICE engine has cylinder walls. Each cylinder wall contains pistons and rings that travel up and down as the engine is running. The piston and rings ensure the air/fuel mixture remains in the combustion chamber while preventing engine oil from getting into the combustion chamber.

That said, warped pistons or cylinder walls will allow fuel to seep into the crankcase and oil into the combustion chamber. If this lingers, it may bend the con rods and pistons, seize the engine from turning or break the engine block.

Q: Can I still drive my car if it overheats?

Whenever you notice a temperature rise in your car, do not panic but safely pull out of the road and allow your engine to cool down. Follow the above steps to cool down your overheated engine.

While an engine overheating may not cause immediate damages to your engine, continuously driving it will cause severe engine damages.

Q: How many times can an engine overheat?

Once your temperature gauge on the instrument Cluster gets to the max high point, it takes between 30-60 seconds to start giving issues in the system. It can cause cylinder heads to warp, swell cylinder walls and pistons, or even seize valves. A major cause is usually a substantial leak in the system.

Q: Should you wait for an engine to cool down before adding oil?

To check your engine oil, ensure your vehicle is parked on level ground so it can give an accurate reading on the oil dipstick. Allow the engine to cool down before adding or checking the oil level.

While it is recommended to check the oil level when the engine is cool, you need to ensure the engine is warm. If your vehicle is hot, allow it to cool within 5-10 minutes before checking or adding engine oil.

Final words

With the detailed step-by-step instructions in this article, you’ve learned how to cool an overheated engine. Remember, several issues can lead to overheating. After cooling an overheated engine, consult a mechanic to track and six the culprit.

Having learned that overheating can ruin an engine if you notice and turn off your engine when the temperature dial starts creeping to the red point and allow it to cool, you won’t incur severe damages.

Cultivate regular maintenance culture and always keep an eye on the temperature gauge while driving.

Osuagwu Solomon

Osuagwu Solomon is a seasoned automotive technician for the past 9 years, and a technical writer. He loves writing about auto professional repair guides, DIY repair guides, and buyer’s guide. After spending six years in the automotive workshop, he decided to impact his knowledge to people aside his domain, and he has achieved this by centering his Automotive writing skills on REPAIRS.

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