Engine Coolant Over Temperature [Meaning, Causes, & Fix]

Engine coolant over temperature can be a serious issue that can cause significant damage to your engine if left unchecked.

Therefore, it’s important to understand the causes of engine coolant over temperature and what you can do to prevent or fix it.

Are you currently experiencing engine coolant over temperature? We recommend you read till the end because, in this post, we’ll explore the causes of engine coolant over temperature. We’ll also provide some tips on how you can prevent or fix it.

Engine Coolant Over Temperature [Meaning, Causes, & Fix]

What is an Engine Coolant?

The engine coolant is a fluid that circulates through the engine to absorb and dissipate the heat generated by the combustion process. The primary function of the engine coolant is to maintain the optimal operating temperature of the engine. 

When the engine is running, it generates a lot of heat, which can cause damage if not properly regulated. The engine coolant absorbs the heat and carries it away from the engine, dissipating it through the radiator.

Therefore, if the engine coolant over temperature occurs, it can lead to several problems. For example, the engine may start to run poorly or even stall, which can be dangerous if you’re driving on the road. Overheating can also cause damage to the engine components, such as the pistons, cylinders, and valves. In severe cases, it can even lead to a blown head gasket or engine failure.

Symptoms Of Engine Overheating

  • Temperature gauge
  • Overheating dashboard warning light
  • Clicking or clanking car noises
  • Steam, smoke, or vapor
  • Unusual engine smells

What Does Engine Coolant Over Temperature Mean?

Engine coolant over temperature typically occurs when the engine’s cooling system fails to control the engine’s temperature, which has risen above the engine’s safe maximum operating temperature. When this happens, the warning light dashboard will illuminate the dashboard.

The risk of engine failure and damage increases as the engine temperature rises. Low coolant levels, a broken thermostat, a damaged radiator, or a faulty water pump are just a few causes of overheating. To stop further damage and ensure the vehicle operates safely, the problem must be fixed as soon as possible.

It’s crucial to stop the vehicle when the engine coolant over temperature warning light illuminates in a safe area. Before trying to find the problem or fix it, let the engine cool down.

What Causes Engine Coolant Over Temperature?

1. Low Coolant

The engine’s cooling system relies on a specific amount of coolant to circulate through the engine and absorb and dissipate heat. If the coolant level drops below the recommended level, there may not be enough coolant to absorb the heat generated by the engine, leading to overheating.

A leak in the cooling system, which allows the coolant to escape, can cause a low coolant level. Make sure the coolant reservoir and radiator cap are working properly.

2. Cooling System Leaks

Leaks in the cooling system can occur due to a variety of reasons. This includes corrosion, wear and tear, or damage from road debris. When the cooling system leaks, coolant can escape, reducing the amount of fluid available to circulate through the engine and absorb heat. This can cause the engine to overheat quickly, and if left unchecked, it can cause severe damage to the engine.

The most common areas of the cooling system where leaks occur include the radiator, hoses, water pump, and heater core. A cracked or damaged radiator can cause coolant to leak from the bottom of the car. Leaks in the hoses that connect the engine to the radiator or the heater core can cause coolant to escape, leading to overheating. A malfunctioning water pump can also cause leaks, which can lead to overheating.

3. Faulty Thermostat

The thermostat is a critical component of the engine’s cooling system. It regulates the flow of coolant through the engine by opening and closing the engine’s water passages. In order to maintain a consistent operating temperature. When the engine reaches the optimal operating temperature, the thermostat opens. Allowing the coolant to flow through the engine and cool it down.

If the thermostat is faulty, it will not allow the coolant to circulate through the engine. Causing the engine to overheat quickly. Several factors, including corrosion, wear, or a buildup of debris, can cause a stuck thermostat.

Signs of Faulty Thermostat

  • A high-temperature gauge reading
  • Low heat from the vehicle’s heater
  • Coolant leaking from the thermostat housing

4. Broken Water Pump

The water pump is a crucial component of the engine’s cooling system. It circulates the coolant through the engine to regulate its temperature. If the water pump is damaged, it can stop the coolant from flowing, which can lead to the engine overheating.

Causes of a Broken pump 

  • Wear and tear,
  • Damage from debris, or 
  • Malfunctioning bearing. 
Signs of a Damaged Water Pump 
  • Coolant leaking from the pump’s weep hole, 
  • Engine overheating
  • A high-pitched whining noise from the pump.

5. Broken Radiator

The radiator is a critical component of the engine’s cooling system. It is responsible for removing heat from the engine coolant before it recirculates through the engine. Over time, the radiator can become clogged with debris, dirt, and rust. This can restrict the flow of coolant and cause the engine to overheat.

A clogged radiator can cause the engine coolant to flow too slowly or not flow at all. Leading to a buildup of heat within the engine. This can cause the engine to overheat, resulting in significant engine damage if left unchecked.

  • Signs of a Broken Radiator
  •  A high-temperature gauge reading
  •  A coolant leak
  •  Reduced engine performance
  •  Poor fuel economy

6. Electrical Issues

These problems can cause the cooling system to malfunction and result in engine overheating. Electrical components, such as the temperature sensor, fan relay, and cooling fan, play a critical role in regulating the engine’s temperature by monitoring and controlling the flow of coolant through the machine.

A malfunctioning temperature sensor can send incorrect signals to the engine control module. Causing the coolant to flow incorrectly, leading to the engine overheating. Other electrical issues that can cause an engine to overheat include a damaged or corroded wire, a blown fuse, or a malfunctioning engine control module.

How to Fix Engine Coolant Over Temperature

1. Replace the Faulty Thermostat

If you discover that your thermostat is faulty, it is essential to have it replaced immediately to prevent damage to the engine. A qualified mechanic can inspect the thermostat and replace it if necessary. Regular maintenance, including flushing the coolant and replacing the thermostat at the recommended intervals, can help prevent a faulty thermostat from causing the engine to overheat.

2. Diagnosed and Repaired Electrical Problems

You can contact a qualified mechanic to help diagnose this issue. They can help you identify the specific problem and replace the faulty electrical component to prevent further engine damage. Checking the electrical connections and the cooling system’s components can help prevent electrical problems from causing the engine to overheat.

3. Check the Coolant Level

Always check the coolant level and flush the coolant at the recommended intervals to help prevent a clogged radiator. In some cases, a clogged radiator may be repairable, but replacement is often necessary to prevent further engine damage. A qualified mechanic can inspect the radiator and recommend the best course of action if they detect a clog.

4. Repair/Replace Faulty Water Pump

You can contact a professional to repair your water pump if you suspect it is damaged. In some cases, a water pump may be repairable, but replacement is often necessary to prevent further engine damage. 

Regular maintenance, such as checking the water pump for leaks and replacing the coolant at the recommended intervals, can help prevent water pump failure and engine overheating.

5. Refill Coolant

Add more coolant, especially when you are sure there is no leakage.

6. Inspect For Leakage

Check the coolant level regularly and look for any signs of a leak, such as a coolant on the ground under the vehicle or visible damage to the radiator or hoses. If you notice a leak, it is crucial to have it inspected and repaired promptly by a qualified mechanic to prevent further damage to the engine.

Read: Hydroboost Brake Pedal Goes to Floor?


Engine coolant over temperature is a serious issue that can cause significant damage to your vehicle’s engine.

Therefore, it is important to be aware of the warning signs of overheating. And also take preventative measures to avoid this problem. 

Regular maintenance of your vehicle’s cooling system is crucial. This includes checking and topping up the coolant level.

By taking these steps, you can keep your engine running smoothly and avoid costly repairs down the line. 

If you do experience engine coolant over temperature, it’s important to take immediate action, such as pulling over.

You can also allow the engine to cool down or seek professional assistance. Remember, taking care of your vehicle’s engine cooling system is key to ensuring the longevity and reliability of your car.