If you notice steam coming from under the hood or the engine coolant over-temperature light turns red, it means your engine is overheating—and it’s not safe to keep driving. Please turn off the air conditioning and find a safe space to pull over. Don’t open the hood immediately to avoid getting burned by the engine. Wait until the engine cools before removing the cap. This guide talks about the common problems that lead to warnings and helps you take the right actions.
What Does the Engine Coolant Over-Temperature Light Mean?
The engine coolant over-temperature light is on to show that the engine temperature has exceeded the normal range. Some cars use a thermometer with “C” (cold) and “H” (hot) to display it, but many new cars will have separate warning lights. This light may not be of the same style. Some resemble a thermometer icon floating above a wavy line, others display text directly on the screen. The engine overheated and needed to be dealt with immediately.
What Are the Signs of an Overheating Engine?
- Check Engine Light On: In some cases, engine overheating can also trigger the check engine light on the dashboard. This generally happens after the coolant temperature warning light.
- Coolant Temperature Warning Light On: This is the most direct signal.
- Temperature Gauge Reading Hot: If your car has a thermometer and you see the pointer running to the red “H” zone, it means the engine is really overheating.
- Steam from the Hood: Looks like smoke, it’s mostly steam. When the coolant temperature boils too high, it turns into steam coming out of the system and gathers into a mass of white gas under the hood.
- A Sweet Smell: Engine coolant has a particularly sweet taste, and if you smell it in or out of the car, it’s probably coolant that’s leaking.
- Thumping or Knocking Noises: Sometimes the coolant boils and bubbles, making all kinds of noise in the cooling system.
Reduced Engine Power (Limp Mode): A lot of modern cars have a protection called “limp mode”. Once the engine overheats, the vehicle reduces engine power. You’ll feel the car accelerate more slowly, which is protecting itself from even greater damage. If you notice any of these signs, take immediate action.
Why Is My Coolant Over-Temperature?
Overheating of the engine is often a potential problem with the cooling system. Let’s look at the most common reasons.
Leaks Leading to a Low Coolant Level
The cooling system includes a hose, radiator, water pump, and warm water tank. Over time, these parts may leak. Once the coolant is lost, the system cannot maintain the normal pressure and liquid volume, and the result is that the coolant is insufficient and the heat dissipation effect is compromised.
Failed Thermostat
The thermostat controls coolant flow. The engine was still cold. It was turned off. When the temperature goes to the normal range, it opens, allowing coolant to flow into the radiator to cool down. Once the thermostat fails, the engine will overheat quickly.
Faulty Water Pump
Water pumps are a core component of the cooling system. The effect is to allow the coolant to circulate continuously between the engine and the radiator. The impeller inside the water pump is broken, or the external transmission belt is broken, so the coolant cannot flow. The engine would heat up.
Radiator issues
When the car is parked or driving slowly (such as in a traffic jam), the cooling fan is responsible for sucking air into the radiator to cool it down. If the fan is broken or there is a problem with the line, there is not enough air volume and heat dissipation at low speed, and the engine is prone to overheating.
Inoperative Cooling Fan
When the car is parked or driving at low speed (such as in a traffic jam), the cooling fan is responsible for sucking air into the radiator to help dissipate the heat. If the fan motor burns or there is a problem with the line, there is not enough air flow at low speed, the radiator does not cool down, and the engine temperature will increase.
Internal Engine Problem
If the engine head gasket burns, the cylinder head cracks, or the engine block cracks, high-temperature exhaust gas may run into the cooling system, or coolant may leak into the cylinder. This will not only overheat the engine but can also cause major problems if not dealt with quickly.
What To Do When Your Engine Overheats?
- Turn off the air conditioning and find a safe place to park: once the engine is overheating, turn off the air conditioner and pull over to a safe position. Then, the heating can be turned on to the maximum, so that the extra airflow from the engine compartment helps cool the engine.
- Allow the engine to cool completely: don’t rush to open the hood and wait at least 30 minutes or more for the engine to cool down naturally. If you open the hood too early, hot steam or coolant may spurt out, and you will easily get burned. Confirm the thermometer is stable before operating.
- Check coolant level: if you’re confident you’re doing it yourself, you can, after the engine has cooled, check the coolant level in the reservoir. If the level is low, fill it up with a suitable type of coolant.
- Observe for leaks: Pay attention to the presence of wet spots, puddles under or around the vehicle, which may be a sign of coolant leakage or may mean problems with other parts of the system.
- Seek professional help: if you notice a leak or the car still overheats after adding coolant, it’s best to check it out with a car repairman or tow it directly to the repair shop. Have professionals check the real reasons. Don’t drive it until it’s fixed.
How To Check Your Vehicle’s Coolant Level?
Once the engine is completely cool to the touch, you can perform a basic check.
- Locate the Coolant Reservoir: This is typically a translucent plastic tank near the radiator.
- Check the Level: The side of the tank will have “MIN” and “MAX” or “COLD” and “HOT” lines. The coolant level should be between these two marks.
- Add Coolant if Low: If the level is below the minimum mark, you have a leak. You can add the correct type of coolant (check your owner’s manual) to get the level back up, but remember this is a temporary fix. The underlying leak must be found and repaired.
Replacing Parts Damaged by an Overheating Engine
Overheating the engine can be a cascade of trouble, ranging from burning out the radiator or cylinder mat to damage to the engine block. Keeping driving in this situation only makes the problem worse. If the technician recommends replacing the parts, you might as well come to FridayParts to buy.
On our website, you can find the right parts for your vehicle in just a few steps. Enter vehicle model information and part keywords, and you’ll soon be able to lock in the right part. We have a rich stock adapted to your model, allowing you to buy OEM-quality replacement parts at an affordable price. Want to keep the engine and engine parts in top condition? Go to FridayParts now to buy the replacement parts you need!
FAQ
What engine temperature is normal?
Generally, the engine’s operating temperature is at about 195 to 220 degrees Fahrenheit. For a while, the water thermometer usually stops in the middle. If the temperature is greatly over this range, it means the engine is overheating.
Is It Safe to Drive When the Temperature Light is on the dashboard?
No. The safest action is always to pull over and call for roadside assistance.
