What are oil coolers?

An oil cooler is a small radiator, separate from the engine's main radiator, that keeps the engine oil at an appropriate, optimum temperature. It is located between the filter and the engine block or behind the main heat exchanger (radiator). Its function is to cool the oil, thereby extending the life of the engine and transmission. It can also be used to cool the oil in automatic transmissions. An oil cooler plays an important role in keeping a vehicle running smoothly by removing heat and removing oil from moving parts.

How does the engine oil cooler work?

The purpose of the engine oil cooler is to help the engine cooling system manage a critical rise in oil temperature. When oil gets too hot, two problems arise.

• First, the excess heat generated threatens to heat the engine to a level that the cooling system cannot handle.
• Second, the oil loses viscosity as it heats up. It becomes more liquid, less viscous, and has a harder time sticking to components.

Oil is probably the one fluid that plays the most important role in the operation of your car. Moving parts rub against each other, and components can also heat up due to external conditions. They need to be lubricated to prevent wear, but the oil itself can get too hot.

The oil enters the oil cooler at a high temperature and then flows through the oil cooler tubes as the coolant circulates around the tubes. This absorbs the heat from the oil, much like an air conditioner, before it is released into the air through the vehicle's radiator.

The oil cooler acts as a water/oil heat exchanger. It can be located in a variety of places in the engine depending on requirements, although it is often located in front of the water cooler to maintain adequate airflow.

Why cool a vehicle's oil?

In internal combustion engines, engine oil is more than just a lubricant. It seals the piston and cylinder and helps cool the engine. Together with the cooling water, it helps maintain optimal thermal balance in the engine. However, if the engine oil is too hot, the lubricating film between the engine's highly stressed moving parts can break, causing serious engine damage. What's more, engine oil ages faster when it's too hot. Since oil cooling through the sump alone is no longer sufficient for modern high performance engines, separate oil coolers are integrated into the oil circuit to cool the engine oil.

What happens if the oil cooler fails?

Air Cooled Oil Cooler

The air-cooled oil cooler core consists of numerous cooling tubes and cooling plates. When the car is running, wind from the opposite direction of the car is used to cool the hot oil cooler core. The air-cooled oil cooler requires good ventilation around it. It is difficult to ensure sufficient ventilation space on ordinary cars and is generally rarely used. This type of cooler is mainly used in racing cars due to the high speed of the racing car and the large volume of cooling air.

Water Cooled Oil Cooler

The water-cooled oil cooler is placed in the cooling water circuit and uses the temperature of the cooling water to control the temperature of the lubricating oil. When the lubricating oil temperature is high, it is cooled by the cooling water. When the engine starts, the oil absorbs heat from the cooling water, causing the oil temperature to rise rapidly. The oil cooler consists of an aluminum alloy shell, a front cover, a rear cover, and a central copper tube. Heat sinks are mounted on the outside of the tube to improve cooling. Heat is exchanged between the cooling water flowing outside the tube and the lubricating oil flowing inside. There is also a structure in which the oil flows out of the tube and the water flows into the tube.

Oil Cooler Maintenance

It is important to regularly check the condition of the oil cooler and its hoses to detect any leaks, cracks or porosity in the hoses. If the hoses are defective, they should be replaced with new ones as soon as possible. In general, however, oil coolers require little maintenance. Occasionally, a connection may leak. In this case, it's usually enough to replace the gasket and the oil cooler will be back in good working order. For recirculating oil coolers, a leak is often indicated by the presence of oil in the coolant expansion tank.

An air-cooled oil cooler that is heavily clogged with dirt and insects cannot perform satisfactorily. It should be cleaned. Never use a pressure washer or steam cleaner. The fine fins can be twisted under the high pressure of the water, rendering the cooler unusable. To clean the outside of the oil cooler, simply spray the cooler with an insecticide and rinse after the prescribed time. It's best to rinse from the back using a hose and low pressure. It is also possible to use a brush that is not too hard to use.

To clean the interior, use an engine cleaner added to the oil while the engine is still hot. Flushing the engine effectively removes residue and deposits throughout the oil circuit, especially on high mileage engines.