A turbocharger is an exhaust driven pump and compressor that increases air intake volume. This improves the volumetric efficiency of an engine. Because a turbocharger is driven by expanding exhaust gases, it is said to be a free source of power boost.
Expanding exhaust gases drive the turbine wheel. It’s fastened to a common shaft that drives the compressor wheel. The compressor wheel compresses the air fuel charge in the intake manifold. This compressed charge is denser in comparison to a normally aspirated engine. Aspirated engines rely on the downward stroke of the pistons to create low pressure or vacuum in the intake manifold. A turbocharged engine's denser charge is forced into the cylinders by the increased intake manifold pressure. This provides additional engine horsepower.
Turbocharged engines are different than normally aspirated engines. They have a lower compression ratio and are port injected. These parts are usually not interchangeable. Premature failure is typically due to a lack of maintenance.
Most turbocharger failures are oil related. Contaminated and unchanged oil result in bearing damage. The bearings spin at very high speeds; they quickly overheat if not lubricated sufficiently. One of the symptoms of a faulty turbocharger is blue gray exhaust. This is because as the turbo fails, oil is mixing in with the air fuel charge and burning off in the cylinder.
Turbochargers are usually cooled by the engine's cooling system. The engine’s cooling system and the lines to the charger must be maintained and functioning properly. Check the air tube and make sure it’s not obstructed or collapsed. Also, make sure no foreign debris or dirt is sucked into the intake by keeping the air filter clean.