This turbocharger compresses intake air before it enters the engine cylinders, increasing the mass of oxygen available for combustion. It is mounted on the engine exhaust manifold and is driven by exhaust gas flow; the compressor wheel on the opposite shaft forces denser air into the intake tract. A failing turbocharger produces a loss of engine power, increased exhaust smoke, and often a whistling or scraping noise from the bearing assembly. This component is manufactured by Holset, whose internal geometry and bearing clearances match the original assembly specifications, preserving the boost-pressure curve that the engine management system expects. On installation, replace all oil-feed and oil-return gaskets and prime the oil supply to the center housing before starting the engine.