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What Causes A Car To Overheat? 7 Possible Reasons And How To Keep Your Car Cool

Your car’s engine needs to remain at an operating temperature of 195 to 220 degrees Fahrenheit to function normally. At the same time, your combustion engine can produce temperatures upwards of 4,500 degrees.

If your engine overheats, it spells trouble.

What causes a car to overheat? Usually, a vehicle overheats if one of the many components of your engine’s vital cooling system either begins to struggle or fail. Low coolant levels, faulty thermostats, water pump leaks, and damaged belts can also cause your engine to overheat.

An overheated engine is a serious problem. Just as your body needs to remain within its core temperature range to complete vita functions, so too does your car’s engine. Overheating can lead to:

  • Decreased combustion power
  • Higher emissions
  • Short engine component life
  • Poor fuel efficiency
  • Failed engines

If your car overheats, you need to find the source immediately. We’ll show you why your engine’s temperature soars and how to keep your vehicle cool.

Seven Reasons Your Car Overheats

Has your car overheated in the last few days or weeks? It could be one of these issues. Some of these reasons your engine overheats are easy fixes that you can do at home, but others require the keen eye of your mechanic.

1. Cooling System Issues

The combustion engine in your vehicle can reach 4,500 degrees Fahrenheit. It goes without saying that your car needs a way to cool down to avoid periodically bursting into flames. The cooling system does just that by pushing the heat away from the engine and outside your vehicle.

Problems with your cooling system, or even failure, is a common culprit in engine overheating. Let your cooling system fail, and you could risk severe damage and even engine failure. Engine failure, in this case, isn’t an if but a when.

2. Low Oil

Motor oil minimizes the friction between the engine’s moving parts, which in turn manages the temperature. If your oil needs a top up, your engine may start to overheat. Oil leaks are another common culprit and require both repairs and regular oil top ups in the interim.

How do you know if your oil needs a top up? You should check your oil levels weekly to make sure it never gets too low. You’ll check it by turning off your car, waiting for a few minutes and then removing the dipstick.

Wipe the dipstick clean and then replace it into its holder and pull it out again. You have enough oil if it falls between the two marks on the dipstick—it varies by model.

3. Low Coolant

Low levels of coolant contribute directly to issues with overheating.

Your coolant begins and ends its cycle in your radiator, but you don’t need to go into it to check your coolant levels. Instead, look at your coolant reservoir and make sure the liquid reaches the “full” line.

If you need to add coolant, add a mix of one part coolant to one part water and fill it up until it reaches the line.

Person touching gray metal rod on vehicle engine

4. Water Pump Failure

Your water pump moves the engine coolant through your cooling system, which absorbs the heat and passes it on to the radiator.

Problems with your water pump (and subsequent issues with your cooling system) contribute to overheating issues. The most common issue is a leak in the water pump, which can cause it to fail.

How do you spot a leaky or failing water pump? If you spot steam pouring out of the radiator and a leak under the front of the car (coolant, not water), then you have a water pump problem. Fix it immediately to avoid cooling system failure.

5. Faulty Thermostat

Your engine features a thermostat that measures temperatures and regulates your cooling system according to what it sees. It governs the coolant to ensure the engine gets what it needs at the right time.

If your thermostat fails, it can’t efficiently manage the coolant, which results in overheating.

6 & 7. Hose & Belt Problems

Three out of four of the noted issues related either directly or indirectly to the cooling system. However, belts and hoses are common causes of overheating that are easy to spot, maintain, and replace.

Your belts and hoses contribute to the cooling system, charging system, and air conditioning by distributing power appropriately. If it fails, these systems struggle. Your heater or radiator hoses in particular also send coolant around the engine.

If the belt snaps or your hose gets blocked, they can’t function as intended.

You can check your belts and hoses on your own, but it’s also good to look at them whenever you change your oil.

How To Keep Your Car Cool: What To Do When Your Car Overheats

Regular maintenance of your engine including and especially your cooling system is the ticket to stopping overheating and preventing damage to your engine. Your goal always needs to be the prevention of overheating because even once can damage your engine.

Here’s what to do when your car overheats and how to keep your car cool.

1. Check Your Fluid Levels Before Any Long Trips

Before you embark on any long-distance driving, make sure your oil and coolant levels are suitable for the road.

Remember that you should check your oil weekly to avoid any surprises and ensure your engine is well-lubricated.

Ideally, you should also store the items you need to complete this task in your car. You should have a tool kit, flashlight (and batteries), and extra coolant or oil for those just in case moments. Don’t forget to store food, water, and blankets as well in case your car overheats and you need to wait for help.

2. Pull Over Immediately

If your temperature light comes on or you see steam or smoke while driving, pull over and turn off your engine immediately. Ideally, do so in a safe space such as in a layby or another area suitable for parking.

Don’t immediately hop out and pop the hood. You’ll want to wait until the car cools or the temperature drops to cool, check to make sure the road conditions are safe, and then get out.

3. Go Through The Motions

Let’s go back to the reasons your car can overheat. You can check man of those on the road on your own.

First, check your coolant level as described above. If you don’t know where your coolant (or antifreeze) reservoir is, check your owner’s manual or use Google. If the coolant levels look good, move on.

While the hood is up, check on your hoses, particularly the upper and lower radiator hoses. Look for disconnected hoses, punctures or potential blocks.

4. Re-Start Your Engine

With all obvious items checked, re-start your engine.

Most older cars are more likely to overheat if run in sweltering weather (90 degrees Fahrenheit and over). The phenomenon is far less common among newer vehicles, but in some cases, your engine only needed a break to cool down. Letting it sit and cool down, and then restarting it might clear your problems.

If you added coolant and things now seem to function well, then carry on driving and keep an eye on your temperature gauge. Be sure also to schedule a tune-up for your car to make sure there’s not a problem flying under the radar.

Is your engine still acting up? Continue to the next step.

5. Drive To A Nearby Service Station

Adding coolant often buys you enough time to get to the nearest gas or service station safely.

While on your way, keep an eye on your gauges, any steam, or fluids. All these factors inform the mechanic and help them identify the culprit much faster.

If your engine continues to overheat, do not drive it further than the nearest service station. If at any point you feel that driving is no longer safe, pull over and call roadside assistance.

Remember, it is incredibly important not to drive an engine that is overheating.

It will cause incredible, irrev​​ersible damage to your engine. If you worry about the cost of a tow truck, know that replacing your engine will always cost most. Plus, you will risk your safety as well as the safety of other drivers on the road.

Regular Maintenance Is The Antidote To Overheating

An overheated engine isn’t a regular occurrence for drivers because it is usually a sign that something—usually in your cooling system—is either very broken or missing. Routine maintenance, as well as double-checking your fluid levels before long trips, helps prevent overheating on the road.

If your engine does overheat, don’t panic. Find a safe place to pull over and turn off your engine. The best-case scenario is that the event is a fluke and caused by heat. However, you should double check your fluid levels before driving on.

Remember, driving with an overheated engine leads to expensive damage, like blown head gaskets or increased wear and tear. If in doubt, protect yourself and your vehicle by calling a tow truck.