M11 Series – Service Manual – 010-999   Air Intake System – Overview

The Combustion Air System on CELECT™ and CELECT™ Plus engines consists of intake air piping, turbocharger, charge air piping, charge air cooler and exhaust gas piping.

On STC engines, the Combustion Air System consists of intake air piping, turbocharger, aftercooler connection and aftercooler, and exhaust gas piping.

The turbocharger uses exhaust gas energy to turn the turbine wheel. The turbine wheel drives the compressor impeller which provides pressurized air to the engine for combustion. The additional air provided by the turbocharger allows more fuel to be injected to increase the power output from the engine.

The turbine and compressor wheels, and the shaft are supported by two rotating bearings in the bearing housing. Passages in the bearing housing direct filtered, pressurized engine oil to the shaft bearings and thrust bearings. The oil is used to lubricate and cool the rotating components to provide for smooth operation. The oil then drains from the bearing housing to the engine sump through the oil drain line. A restricted oil drain line can cause the turbocharger bearing housing to be pressurized, causing oil to leak past the seal rings.

NOTE: An adequate supply of good, filtered oil is very important to the life of the turbocharger.