Cooling is vital in an engine to absorb heat, and the oil cooler is a device that does just that. Oil cooling uses engine oil as a coolant to remove excessive heat from internal combustion engines. Keeping engine components at their normal working temperatures improves performance and extends service life.
In this reading, we’ll explore what an oil cooler is, its function, diagram, types, and how it works. We’ll also learn its advantages and disadvantages.
Let’s get started!
What Is an Oil Cooler?
An oil cooler is a mechanical device that is used to remove surplus heat from internal combustion engines through a heat exchanger. The device is used for cooling various mechanical parts using oil. These parts include the engine, transmission system, etc.
The device is in the form of a small radiator located in front of the water-based radiator system. Its primary purpose is to lower the temperature of the vehicle while running. That’s the component that works only when the vehicle is running.
Function Of An Engine Oil Cooler
The oil cooler’s job is to maintain the oil at the proper operating temperature, which is between 230 and 260 degrees Fahrenheit. They are heat exchangers, which act similarly to a car’s radiator. The purpose of their large surface area is to radiate as much heat as possible to the surrounding air or coolant, depending on the kind of oil cooler.
Oil-to-air oil coolers are usually placed next to the radiator, behind the grilles of the car. This area delivers the most airflow, which is required for optimal heat dissipation. The cooled oil serves a lot of purpose for the high-stress transmission oil. Engines with cooling fans rapidly cool both the water- and oil-based radiators, which is why they offer additional benefits.
By acting as an extra cooling mechanism, the oil cooler can significantly lower the high temperature in air-cooled engines. This will greatly extend the engine’s lifespan. Oil coolers are beneficial for heavier trucks because they reduce strain on the drivetrain.
This improved cooling system not only keeps the engine oil from overheating but also keeps it from breaking down too soon.
Related: What Is Oil Pump? Its Types and How it Works
Diagram Of An Oil Cooler
Types of Engine Oil Coolers
Engine oil coolers can be generally classified into two types, such as oil-to-water and oil-to-air.
Oil-To-Water Cooler
In these types of oil coolers, the coolant passes through a heat exchanger element of some parts. The coolant is enabled either by adding heat to cold oil or drawing heat from excessively hot oil.
Oil-To-Air Cooler
is a small radiator that enables the engine oil to be cooled directly from ambient air from the cooling fans. Most of oil-to-air coolers work with a thermostatically controlled bypass valve that stops the engine oil from passing through the cooler without reaching its desired operating temperature.
The various types of coolers include the basic tube-and-fin style, where the oil passes through a single or multiple coolers. Some other types may have multiple cooling rows or have a stacked plate type. Some oil coolers are header-style, where the end tanks are designed like a radiator.
How An Oil Cooler Works
Oil coolers normally work by moving air from the engine to the oil. If your car’s engine is in the front, air flows through a hole in the bumper and over a bunch of small metal fins that keep the oil cool. The oil cools as it flows through small holes behind the fins.
Your coolant is cooled in the same way that a few other cars are cooled: it flows past the hotter oil in a heat exchanger, which keeps the coolant cool.
In the working of oil-to-air coolers, they are usually mounted in front of the radiator, although they are of the same shape. This gives the engine oil quick access to the coldest fresh air from the cooling fan. In most cases, the oil passes from the engine in the form of a “sandwich” adapter.
This adapter is mounted between the oil filter and the engine block as it allows hot oil to flow through the filter before going back to the engine. Some of these sandwich adaptors are designed with thermostatic control that disables oil from flowing until it reaches a specific temperature.
Some systems are designed with a remote that is mounted on the oil filter and an additional adapter that uses the existing oil filter. The existing oil filter mounts to plumb hoses to the cooler and the remote filter base.
There is often an inline thermostat that offers the same bypass function. In vehicles where there is no space to mount at the front of the radiator, manufacturers provide coolers elsewhere in the engine. Some even feature their own cooling fan. This design is much like the dry-sump lubrication system.
Related: What Is An Engine Lubrication System? Its Functions And Parts
Advantages
Below are the benefits of an oil cooler in an internal combustion engine:
- With a thermostat, the oil cooler cools hot oil at an exact temperature.
- It ensures proper cooling of oil before circulating.
- The temperature of the oil is controlled in the oil-to-water cooler.
- Installation of oil coolers is quite easy.
- Generally, an oil cooler enhances the working of an engine.
- It decreases the use of a water cooling system as it can be corrosive to the engine.
- As oil drastically serves as a coolant, extra coolant tanks, pumps, and radiators are eliminated from the engine design.
- Oil circulation is efficient and controlled.
Disadvantages
Despite the good advantages of an oil cooler, some limitations still occur. Below are the disadvantages of the engine part:
- Unlike water, the oil may be flammable.
- Extra oil is required to operate the oil cooler.
- Extra maintenance must be done.
- Thermostat failure will stop the circulation of oil, especially if permanently locked.
- Overcooling may occur if the valve is permanently open.
Symptoms Of Bad Oil Cooler
Car oil coolers can eventually fail due to wear and tear. Your car may exhibit a number of symptoms when this occurs, including the following:
Oil Mixing With Coolant
The oil cooler is made so that the water and oil are kept separate. Small cracks can form inside a broken oil cooler, letting oil and coolant mix.
Oil Leaks
The oil cooler and the engine’s oil lines are connected via an oil cooler adapter. There is a chance that oil will leak out of the engine and pool under your car if there is damage to either the cooler’s adapter or the o-ring connecting the cooler to the adapter.
Oil can also leak from the oil cooler. A leaking oil cooler is a major problem since it can lead to low oil levels, depriving your engine of its lubricating and cooling capabilities.
Low oil levels can eventually lead to overheating or even engine seizing. Contacting a reputable repair shop as soon as you see oil seeping out of your car is advised to ensure the leak is quickly sealed off.
Coolant Leaks
Oil-to-water oil coolants can leak coolant because they employ either oil or water. When this happens, the coolant in your car may run out. This could lead to an overheated engine.
Engine overheating can result in cracked engine blocks, warped pistons, and leaking gaskets. Additionally, the engine may produce terrible grinding and knocking noises. If left running, the engine may seize up or sustain serious damage.