5 Reasons Why Truck Engine Overheats

Why truck engine overheats is still something that many truck owners have never understood. The engine generates heat when functioning. It has metallic moving parts that rub against each other, and the combustion chamber creates heat as compression occurs. Friction and compression are sources of heat within the engine. Sometimes the temperature of your engine can be more than optimum. In such a situation, your engine will overheat

The engine has got cooling system whose primary responsibility is to cool down the engine. There are various reasons which might lead to an increase in the engine temperatures.

Reasons Why Truck Engine Overheats

Stuck Thermostat

The thermostat within the engine plays the role of regulating the temperature. The thermostat closes and opens. During cold weather, the thermostat remains closed and opens when the engine starts to warm up. When the thermostat opens, the coolant will flow into the radiator. 

The radiator plays the role of conducting the heat from the coolant to the air outside, which regulates the engine’s temperature.

If the thermostat fails to open, the coolant will not be able to travel to the radiator, and the truck engine will overheat.

Faulty Water Pump

It is the power from the engine that drives the water pump. Engine accessories like the timing belt or the timing chain propel the water pump. The water pump has an impeller that looks like the blades of a fan.

The impeller spins whenever your engine is running, and its rotation is what pushes the coolant through the cooling system. If the belts that drive it are faulty, the coolant will not be able to move correctly within the system, leading to engine overheating. 

Coolant Leaks

The coolant can leak inside your engine, and a cracked cylinder head, engine block, and damaged head gasket are some of the causes of coolant leaks within the engine. When the coolant leaks and gets into contact with the oil can lead to contamination. Sometimes, the coolant might get into the combustion chamber and be consumed. All this will reduce the level of the coolant. 

When the coolant hose leaks out coolant, the engine will overheat the gasket head will blow out.

Faulty Radiator Fan

The radiator fan is a crucial part of the cooling system, located between the engine and the radiator. The radiator fan has blades and is part of your truck’s electrical system. Its primary role is to blow off hot air in the coolant from the engine to cool it down. 

When the fan is faulty, it will not be able to cool down the coolant from the engine, and the hot coolant will be pumped back into the engine, which will make your engine overheat. 

Failed Temperature Sensors

The role of the temperature sensors is to determine when to turn on the radiator fan. When the temperature sensor malfunctions, the fan will not be able to turn on, and your engine will overheat.


When your truck’s engine is overheating, it is a severe condition you should not ignore. Consider visiting your mechanic to determine the exact cause of such a situation. In this guide, you have seen some of the reasons why truck engine overheats.

How To Know Your Truck Is Overheating

The truck’s engine produces a lot of heat. The heat comes from the active combustion in the engine cylinders and friction from the engine’s moving parts. High temperatures are likely to destroy the engine parts. Engineers invented the cooling system to contain the temperature of trucks. In this guide, we will go through some of the pointers on how to know your truck is overheating and what to do when that happens.

How To Know Your Truck Is Overheating

Rise in temperature during summer, or when the cooling system is faulty, the ability of your truck to cool the engine effectively will go down. Here is how to know that your engine’s temperature rises above average. 

When your Truck Struggles to Perform

An overheating engine will not effectively accelerate. The hot air in the engine expels the cold air. It is the cold air that gets into the cylinder, mixes with fuel, and facilitates the process of combustion. If the explosion is not actively taking place in the cylinders, you will realize that the truck does not respond whenever you accelerate.

Engine smells

When your engine is overheating, you will smell the heat. Three kinds of smells indicate that your engine is overheating.

Burning Plastic Smell – when you feel this smell, your engine’s plastic parts start to melt.

Sweet Car Smell – the coolant is made of an organic compound called ethylene glycol. When your engine is overheating, this compound burns, and you will feel a sweet smell.

Burning Oil Smell – The engine oil produces a sulfur-like smell when burning. 

When Your Truck Produces Steam or Smoke

The radiator cools the engine. It has fluids composed of water, corrosion inhibitors, and antifreeze. The boiling points of these fluids are higher than the engine’s operating temperature. When the engine is overheating, its temperature will go beyond the boiling point of the fluids in the radiator. The state of the liquids will change, and they will start to evaporate. You will see steam or smoke escaping from your engine.

Clicking Sound

Engine oil does the role of lubricating and ensuring that the engine’s moving parts move smoothly. The engine’s moving parts will produce a clicking sound because they will lack oil to keep them smooth as they rub against each other. If your engine overheats, the engine oil wears out and becomes inefficient in lubrication.

Temperature Check Light Appearing on the Dashboard

When your engine is overheating, your dashboard will notify you by lighting a thermometer seated on waves. The thermometer on waves indicates that the radiator fluids’ temperature is going up due to an overheating engine. 

The Temperature Gauge

The temperature gauge does not give you the temperature of the surrounding. Instead, it tells you the actual temperature of your engine. As your engine’s temperature rises, you will see it on the temperature gauge. The gauge has a red area. If it reaches the red zone, your engine is scorching and can be damaged anytime.


Overheating engines can lead to severe repairs, such as an expensive overhaul that takes time to fix. Sometimes, it can force you to change the entire engine. It is necessary to take precautions and stay alert when your engine starts to overheat.