Smoke rising out of your engine compartment?
This is a common sign of a car overheating.
Low coolant levels or a faulty radiator cap are common culprits to look out for.
Curious about what else could cause this issue and how to address it?
We’ve got you covered!
We’ll discuss why a car overheats, what to do when it happens, and some helpful prevention tips.
This Article Contains
- 8 Most Common Reasons for Engine Overheating
- What to Do If Your Car Begins to Overheat
- 4 Signs of an Overheating Engine
- How Much Does It Cost to Fix an Overheating Car?
- 5 Tips to Prevent Your Car From Overheating
8 Most Common Reasons for Engine Overheating
Engine overheating happens for many reasons, including:
1. Faulty Thermostat
Your car’s engine thermostat helps regulate engine temperature. When the engine is cold, the thermostat remains closed, preventing engine coolant from moving to the radiator. Once the engine warms up, the thermostat opens to allow coolant to flow into the radiator.
The radiator acts like a heat exchanger, transferring excess heat from the coolant to the outside air. This keeps the engine operating temperature within the optimum range — around 195°F-220°F (75°C-105°C).
If the thermostat gets stuck in a closed position, it restricts coolant flow to the radiator, which leads to your car overheating.
2. Broken Water Pump
Your car’s engine powers the water pump through an accessory belt, timing belt, or timing chain.
The water pump housing also contains a rotating component called an impeller, which has fan-like blades. Anytime the engine runs, the impeller spins and pushes the coolant through the car’s cooling system.
But if you have a broken water pump, coolant will no longer circulate properly, causing the temperature gauge to spike and the engine to overheat.
3. Radiator Issues
The radiator must be free from internal and external obstructions to dissipate excess heat from the engine.
Why?
An internal blockage can obstruct coolant flow through the radiator, while an external obstruction can prevent airflow across the device. Both clogging issues can lead to excessive heat in the engine.
In addition, a bad radiator cap could result in a low coolant level due to leaking, which reduces the engine’s cooling effect.
4. Coolant Leaks
Coolant leaks can occur anywhere in your cooling system, including the water pump, radiator, coolant hose, and coolant reservoir. A large coolant leak can cause you to lose precious radiator fluid.
Besides the coolant system, leaks can also develop inside the engine block — often due to a damaged head gasket or engine block crack. This leads to cross-contamination between the fuel and radiator fluid, followed by low coolant levels.
Note: Internal coolant leaks often stem from an overheating problem that began elsewhere. For example, a leaking radiator hose can lead to a low coolant level, resulting in a blown head gasket and an overheated engine.
5. Faulty Cooling Fan
When you drive your car, air flowing through the radiator cools the coolant and lowers the engine temperature. However, a radiator fan is necessary to dissipate excessive heat when the car is idling or when the engine runs at a high temperature (220°F).
So, when the cooling fan fails your engine overheats.
6. Failed Engine Coolant Temperature Sensor
In modern cars, an onboard computer controls the radiator fan operation. The computer relies primarily on the engine coolant temperature sensor data to determine when to turn on the fan. If the temperature gauge fails, the computer might not operate the fan properly, and you may experience an overheating issue.
7. Low Engine Oil
Extremely low engine oil levels can cause an overheating issue. That’s because engine oil reduces friction between the moving parts of the engine by lubricating them. This brings down the amount of heat released by the engine.
So if your car overheats and your oil light and check engine light turn on, you may have low oil.
8. Worn Drive Belt
The drive belt helps the water pump circulate coolant through the cooling system. However, if the drive belt wears down due to aging, misaligned pulleys, or incorrect tension, it may prevent the water pump from doing its job. This inhibits the coolant fluid from cooling the engine, causing the engine to overheat.
Knowing why your car overheats is essential for fixing the issue. However, you also need to know what to do if this happens.
Let’s take a look.
What to Do If Your Car Begins to Overheat
If your car engine overheats, the first thing you should do is slow down and find a safe parking spot to avoid further engine damage.
However, if you have no choice but to keep driving, then:
- Turn off the air conditioning and other accessories: This helps reduce stress on the engine.
- Crank up the heater: It helps pull excess heat out of the engine.
- Open all windows and drive at a steady speed: Natural airflow can help reduce engine heat and steady speed minimizes engine load.
Once you’ve stopped safely, immediately turn off the engine and call for assistance. While waiting for your roadside assistance mechanic or tow truck to arrive, you should:
- Open the engine compartment: Do this only after you let the engine heat dissipate — opening the hood immediately could cause the steam to burn your skin.
- Check the coolant level: If there’s low coolant, top it up to ensure there’s a sufficient amount.
- Inspect the radiator for any blockages: Sometimes, a huge piece of plastic can get stuck and cause overheating.
- Check the engine oil level: Refill the reservoir with fresh engine oil.
If your car overheats and you don’t get it inspected immediately, you’ll need a good car insurance plan to cover the costly engine repair jobs.
Let’s examine the crucial signs you need to watch out for.
4 Signs of an Overheating Engine
To prevent severe engine damage caused by overheating, look out for these indications:
- Steam or smoke coming from the engine compartment
- Higher temperature gauge readings (the needle spikes to the red or “H” end)
- Strange smells from the engine compartment (sweet if there’s a coolant leak and burnt if it’s an oil leak)
- An Illuminated temperature and check engine light
Now that you know about the signs of an overheating car, let’s see how much you can end up paying for the repair.
How Much Does It Cost to Fix an Overheating Car?
Expect to spend between $100 to $3,000 to fix an overheating car, depending on the exact issue.
Here are some estimates to replace possible problematic components (including labor):
- Drive belt: $110 to $135
- Engine coolant temperature sensor: Around $130
- Coolant leaks: $150 to $400
- Cooling fan: $150 to $900
- Thermostat: $200 to $550
- Radiator: $200 to $900
- Water pump: $400 to $1,000
- Blown head gasket: $1,000 to $3,000
Want to avoid these expensive replacement charges?
Check out some preventative measures you can take.
5 Tips to Prevent Your Car From Overheating
Here are the steps you can take to prevent overheating:
- Always check your engine oil condition and coolant level before leaving for a long trip.
- Keep a fresh bottle of coolant fluid and a gallon of water in your car for emergencies.
- Never skip car repair, regular maintenance, and inspection appointments, such as an oil change or coolant system flush.
- Don’t overuse the air conditioning, especially on extremely hot days.
- When driving long distances, always take a break to reduce engine heat.
As long as you care for your overall car maintenance, you’ll easily prevent overheating.
Keep Your Engine Cool with AutoNation Mobile Service
Several issues cause an overheating problem, including a blocked radiator or a leaking radiator hose.
Ignoring these problems could result in a costly engine repair, so pull over and shut the car engine off as soon as you notice any signs of overheating.
Don’t want to damage your car by driving to the mechanic?
AutoNation Mobile Service will come to you to fix your vehicle.
We’re a mobile auto repair and maintenance service offering upfront pricing and a 12-month, 12,000-mile repair warranty.
Contact us today to get your overheated engine repaired or for any other car maintenance.