The charge-air cooler and turbocharger are part of a high tech induction system that increases engine combustion efficiency. The turbocharger uses exhaust gases to compress air before it enters the charge-air cooler.
The compressed air going through the charge-air cooler is then cooled by the ambient air flowing across the cooler fins. The cooled air is more dense than warm air. So when it flows into the intake side of the engine, the increased density improves horsepower, fuel economy and reduces emissions. The following illustration provides a clear view of the components associated with the charge-air-cooler and how the air flows through the system:
Charge-air coolers can develop leaks and can fail if not caught soon enough. A leaking charge-air-cooler can cause the engine to lose up to ½ mpg in fuel economy. To maintain engine power and engine and fuel efficiency, it is important to properly test all charge-air coolers periodically.
Causes that contribute to failures (in order of probability) are:
• Heat stress (most common)
Charge-Air-Coolers come in many different sizes and configurations depending on the vehicle application they are used. No matter what application, the basic components of the unit are the same. These components consist of:
• Inlet and Outlet tanks, or manifolds as they are sometimes called • The main core consisting of the internal fins, external fins, and tubes • The header plate that is welded to the core and used to attach the tanks • The brackets that are used to secure the charge-air-cooler to the vehicle • Finally, the top and bottom plates
Please refer to the diagram below to see how these components are combined to produce the complete charge-air-cooler.
Although same model coolers may look the same, there can be many differences in the quality of the materials used, the brazing processes to attach each component, and the type of core construction used. We will discuss these differences in detail in the next section.
Although cores look alike to the average eye, there are vast differences that have a tremendous impact on overall performance and durability. The three main areas of the construction are:
• Overall design of the core
There are two types of tube designs – extruded tube and the folded/weld seam design. The walls of the tube should be thicker to withstand burning out from excessive heat, especially the top and bottom tubes. In addition, the thicker walls will protect the tube better against corrosion. Due to the fact of having no potential seam failure and the ability to use higher quality alloys in the production stage, we find the extruded tubes to be stronger and more efficient.
The inner fins of the tube are critical to air flow and cooling. The number of fins per inch, position and spacing of these fins will determine the most efficient flow of air through the cooler.