Why Is Your Car Engine Overheating?- 6 Possible Causes

Today’s cars have sophisticated cooling systems equipped with multiple heat sensors and computer-controlled electric fans designed to keep your engine running in any weather. But overheating can still happen.

Why Do Engines Overheat?

Engines can overheat for many reasons. In general, it’s because something’s wrong within the cooling system and heat isn’t able to escape the engine compartment. The source of the issue could include a cooling system leak, faulty radiator fan, broken water pump, or clogged coolant hose.

Regardless of the problem’s source, an overheating engine isn’t something you want to let linger. Your engine could sustain serious, if not permanent, damage.

Signs Your Engine is Overheating

If you’re able to take steps to cool your engine before it overheats to the point of failing, you may reduce the risk of irreversible engine damage. But first, you’ve got to notice the symptoms of overheating, which can include:

  • Steam (which can look like smoke) coming from under the car hood.
  • An engine temperature gauge on your dashboard that spikes to “H” or into the red. (Engine temperature gauge symbols vary, so consult your owner’s manual.)
  • A strange smell coming from the engine area. For example, leaking coolant can smell sweet while leaking oil might smell more burnt.

As soon as you notice the engine overheating, take the following steps and contact your nearest repair shop.

What Causes a Car To Overheat?

Generally, an overheating engine means that there’s something wrong with the cooling system. After all, this system is designed to move excess heat away from the engine. Below are five major problems that can develop within this system.

1. A Malfunctioning Thermostat

The thermostat keeps the coolant from entering the engine until the engine has warmed up. This means your car can reach operating temperature faster. However, if the thermostat is broken, it may not open and let the coolant flow in when it needs to.

2. A Damaged Water Pump

Coolant is a mixture of water and antifreeze (which keeps the water from freezing in low temperatures). So, a water pump is what pumps the coolant through the engine, where it absorbs the extra heat. A problem with the water pump means that the coolant’s flow may be impaired or it may not flow at all.

3. Low or Contaminated Coolant

Of course, even if the water pump works, it won’t do much good if there’s something wrong with the coolant itself. If there’s not enough in the system, it will be inadequate to cool the engine. And if the coolant has contaminants, it won’t work as effectively, and may not absorb as much heat.

4. Bad Hoses

The hoses are what the coolant moves through as it goes between the engine and the radiator. Damaged, cracked, loose, or clogged hoses may cause the coolant to leak, or they may simply impede the flow of coolant.

5. Damaged Radiator

The radiator itself is where the coolant goes to get its cool back. So if the radiator has suffered damage, the coolant may stay too warm. There are many things that could go wrong with a radiator. For example, the radiator fan could have burned out, or the radiator itself may have sustained physical damage from an accident.

Though radiators can sometimes be repaired, it’s usually a good idea to have them replaced.

What to Do When Your Engine Overheats

1. Kill the A/C and crank the heat.

Immediately turn off the air conditioner to reduce stress on the engine. Then, turn the dial to maximum heat. This can help pull heat away from the engine to keep it from overheating until you can pull over in a safe location. You may get a little hot yourself, but a few minutes of discomfort is a small price to pay compared to major engine repairs.

2. Find a safe place to pull over.

Pullover and shut off the car. Allow the engine to cool for at least 15 minutes. Keep an eye on the temperature gauge, as it should move back to a normal range as the engine cools.

While you’re waiting (and watching the gauge), put together a plan to get your overheated engine checked out.

3. Check and add coolant (if you have it).

If your coolant level is low, a quick top-off could help protect your engine and prevent overheating until you can get things fixed. However, this step won’t do much good if a coolant hose is clogged or the source of your troubles is a broken radiator fan or water pump.

Consult your owner’s manual to find the location of your coolant reservoir tank and to learn how to add coolant to your vehicle.

4. Restart the engine.

If your car isn’t being towed, now’s the time to carefully restart your engine and drive to your nearest auto repair shop. Keep an eye on the temperature gauge as you drive. If it rises again, pull over and let the system cool.

What Not to Do When Your Engine Overheats

1. Don’t panic.

Your engine isn’t keeping its cool, but you can! Avoid swerving through traffic or slamming on your brakes when pulling off the road.

2. Don’t keep driving.

If your engine is overheating but still running, you’re not doing it any favors by staying on the road. Sure, you may be able to get to your destination before it gives out entirely, but you may cause significant (and costly) damage by pushing your engine too far.

3. Don’t open the hood immediately.

Once you’ve pulled over, wait for the engine to cool before popping the hood to check things out. Opening the hood immediately can put you at risk of burns or injuries from spewing steam or smoke. Patience is key. Wait until the engine temperature gauge settles before opening the hood.

4. Don’t let the issue linger.

An overheating engine won’t resolve on its own, even if it seems to be fixed after you add a little coolant. It will only get worse if left unaddressed. Get to the root of the issue to help save your engine.

How to Prevent an Overheated Car Engine

Take care of your car, and it’ll take care of you. The best way to prevent an overheating car engine is to have regular coolant flushes and exchanges performed on your car, and stay up-to-date with radiator maintenance as recommended by your vehicle manufacturer. Routine inspections can also help you fix any potential radiator or engine issues before they worsen.