By Lawrence Reaves
Several factors can cause your car’s engine to overheat. Most people realize a lack of motor oil is a common culprit, but there are many other issues that can play a role. Unfortunately, an overheating engine usually means costly repair bills, and may even warrant an overhaul.
In this article, we’ll present the most common reasons an engine will overheat. As you read through the following list of factors, you’ll note that nearly all of them are within your control. Learn to identify signs of problems before a trip to the repair shop becomes necessary.
A Leak In The Cooling System
While most people think of insufficient oil as the number one cause of an overheating engine, experienced mechanics would point to the cooling system. Coolant courses through the system to help control the temperature surrounding the assembly. When a leak develops, coolant escapes. As the level of fluid drops, the temperature rises until an overheating problem occurs.
Get into the habit of periodically checking the hoses for cracks. You’ll also need to check near the cylinder head, heater core, and radiator, to make certain coolant is not leaking from any of these points.
Failing Water Pump
The water pump is arguably the most important component of your vehicle’s cooling system. Small impellers within the component turn in order to pump coolant to your engine. If the pump fails, fluid will be unable to reach the assembly, causing it to overheat.
Many water pumps are designed with impellers that are made of plastic. They wear down and break off more quickly than normally occurs with metal impellers. In some cases, they loosen. When these things happen, coolant will be prevented from circulating through the engine.
Malfunctioning Thermostat
A thermostat monitors the operating temperature of your engine. It influences whether coolant is allowed to flow to the radiator in order to release absorbed heat. If the engine is running cool, the fluid is prevented from returning to the radiator until the assembly heats up.
The thermostat essentially functions like a valve. It opens and closes according to its temperature reading. If the part fails, it can stick in a closed position, which will block the passage of coolant. For reasons described earlier, this will cause overheating.
Blown Head Gasket
The head gasket sits between the engine block and cylinder head; it prevents coolant from entering the crankcase and combustion chambers. The gasket can fail when the block and head expand due to heat. They are constructed of different types of metal, and thus their respective thermal expansion rates are different. As they expand, the gasket is exposed to stress. Eventually, it can fail.
A blown head gasket causes coolant to leak from the cooling system. As a result, less fluid is available to absorb heat from the engine. This can cause the temperature to climb until the assembly overheats.
Clogged Radiator
When coolant flows to the radiator, it moves through a series of passages. As it flows, its absorbed heat is allowed to escape through small vents. Over time, the radiator can become clogged as a result of accumulated dirt and debris. This problem can also occur due to corrosion and rust.
When the radiator becomes plugged, heat is not able to dissipate properly. Instead, it remains trapped in the coolant, which flows back to the engine. Because the fluid is still hot, it less able to control the temperature surrounding the assembly. Overheating will become a possibility unless the problem is resolved
Insufficient Motor Oil
As a vehicle ages, its engine becomes more susceptible to oil leaks and excess consumption. Starved of oil, the assembly’s moving parts will rub against each other. This creates friction, which not only damages the components, but can also cause the temperature in the engine to rise.
An overheating engine will often lead to detonation inside the cylinders. The air-fuel mixture will essentially explode unpredictably instead of burning via normal combustion. This, in turn, can cause the pistons and valves to slam into one another. If you notice overheating, pull over to the side of the road, and turn your car off. Driving it further will lead to expensive engine damage.