Charge Air Cooler

June 24, 2005, 09:23:35 pm

There is some confusion about the cooling system and the Charge Air Cooler. Even though they are mounted right against each other, they perform distinctly different functions.
If you looked for a charge air leak you wouldn't see any fluid and could only see a defect if the crack was visible because the CAC does not contain cooling fluid (anti-freeze), it is charged with air. A turbocharger is basically an air pump. Hot exhaust gases leaving the engine after combustion are routed directly to the turbine wheel side of the turbocharger to make it rotate. That turbine wheel is connected by a shaft to a compressor wheel. As the turbine wheel spins faster and faster, it causes the compressor wheel to also spin quickly. The rotation of the compressor wheel pulls in ambient air and compresses it before pumping it into the engine's chambers.
As you may have guessed, the compressed air leaving the compressor wheel housing is very hot as a result of both compression and friction. So what's needed is a way to cool that air down before it enters the chambers. That's where a charge-air cooler (or "heat exchanger") comes in. It reduces the temperature of the compressed air so that it is denser when it enters the chamber (heat causes things to expand, as we all learned in science class). The charge-air cooler also helps to keep the temperature down in the combustion chamber. All together, the engine, turbocharger and charge-air cooler form what is known as a "charge-air system". of the engine.
If the engine overheats, the CAC can be a contributing factor due to loss of power and proper operation of the turbo charger, etc. Most likely it is not the proximate cause of overheating.
If you have a Silverleaf, you can see loss of horsepower and torque and a defective CAC is always suspect.

Larry
Intrigue
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