Reasons a Car May Overheat - Service Information at Capitol Chevrolet

Of all the problems your car might have, an overheating engine is one of the most serious. If the engine gets too hot, it may begin to warp and crack, causing sometimes irreparable damage. But what causes an engine to overheat? We'll go over six potential causes below.

But before we get into what could be causing your engine to overheat, we'll take a moment to let you know what you should do if you have this problem. The first thing to do is to turn off the A/C, roll down the windows, and turn the heater on full blast. This may be uncomfortable in warm weather, but it's better than losing your engine. Then, pull over to the side of the road as soon as you can safely do so and shut off the engine.

Engine coolant reservoir

6. Low Coolant

We mentioned that engine in your Chevy produces an incredible amount of heat. The cooling system helps remove much of the excess heat, and coolant is what does most of the work. It absorbs heat from the engine, then moves to the radiator where it's cooled down. Once it's lost the heat, it cycles back through the engine. So, if your cooling system doesn't have enough coolant, it won't be able to work as effectively. This, in turn, will cause the temperature of the engine to rise. We recommend checking the coolant levels regularly, since it's easy to take a quick look while you're checking your oil or refilling your wiper fluid. If you are losing coolant due to a leak, it's important to get an inspection so technicians can pinpoint the source of the leak.

Two thermostats and a water pump

5. Faulty Thermostat

The thermostat controls the flow of the coolant. When your engine is just starting, the thermostat valve stays closed, and the coolant doesn't circulate. Once the engine reaches operating temperature, the valve will open and coolant will begin to flow through the engine. A faulty thermostat might remain closed even when the engine is hot, which can quickly lead to overheating.

4. Bad Water Pump

The water pump is what circulates coolant through the cooling system. It's called this because coolant was at one time simply water. These days, coolant is a mixture of water and antifreeze, but the original name stuck. If the water pump is faulty, coolant may not circulate as well, or may cease to circulate entirely, leading to an overheating engine even if your coolant levels are fine.

Head gasket assortments

3. Damaged Radiator or Cap

The radiator is where the coolant goes to lose its cool, so to speak. The coolant travels through tubes in the radiator. Fins that are attached to these tubes collect the heat from the liquid, and the air that passes over the radiator moves the heat away. If the radiator has suffered physical damage in an accident, it may not be able to do this as effectively.

In addition, the radiator cap is designed to keep your cooling system pressurized. If the cap is damaged, the coolant may simply boil off and escape the system instead of being properly cooled.

2. Damaged Radiator Fan

We mentioned that the air that flows over the radiator helps remove the heat that the fins have grabbed from the coolant, but air only does that when your car is moving. So, when your vehicle comes to a stop, the radiator fan will kick in. This fan moves air across the radiator. If it's broken, your car may begin to overheat when it's idling, only to cool down again once you start moving.

1. Blown Head Gasket

The head gasket in your vehicle keeps the engine block and the cylinder head separate. If it blows, coolant can get into the combustion chamber and oil can get into the cooling system. Though this can cause a visible coolant leak, it can also cause lower coolant levels without a visible leak. You may also notice milky-white oil and white smoke coming from the exhaust pipe.

Related Articles

We offer professional service and repairs at
Capitol Chevrolet
Order parts online from Capitol Chevrolet located in
Salem, OR



2855 Maple Ave Ne
Directions 2855 Maple Ave Ne
Salem, OR 97301

  • Contact: (503) 877-2943


  • Monday 7:00 am - 6:00 pm
  • Tuesday 7:00 am - 6:00 pm
  • Wednesday 7:00 am - 6:00 pm
  • Thursday 7:00 am - 6:00 pm
  • Friday 7:00 am - 6:00 pm
  • Saturday 8:00 am - 5:00 pm
  • Sunday Closed