Toyota 17201-42011 TURBOCHARGER Sub-Assembly

The turbocharger is basically a mechanically uncomplicated component; however, it is defined by its high precision and can be irreparably damaged by interrupted oil or coolant supply or loose or damaged ducts. Because it may take specialized tools and procedures, it is advisable to avail of a dealer service department to check and diagnose cases that may seem problematic, however, the home mechanic is capable of visually observing connections and linkages for tightness, signs of damage or other basic troubles. Both turbochargers make individual sounds, and a variation in the noise is considered unhealthy; for example, a high-pitched whistling sound implies a problem with the inlet air or exhaust gas leakage. When any strange noises are produced in vicinity to the turbine, the turbocharger is withdrawn for the inspection of the turbine wheel, all these procedures are to be done with the help of engine off and cool to avoid any hazards on individuals. The engine should not be running when attempting to turn the turbine wheel as an indication of a worn turbine bearing; the wheel should turn freely; if not, overheating can cause the cooling oil to sludge or coke. Also, the exhaust manifold should be inspected for crack and loose joints. Since the turbine wheel can turn up to 110 000 revolutions per minute, interruptions in the supply of coolant or loss of oil essentially result in critical damage and, therefore, one has to check for leaks of coolant and obstructions in the inlet of oil as well as in the oil drained back line due to massive loss of oil through turbocharger seals, apparent by burnt oil on the turbine housing. It is always necessary to flush the turbocharger with clean oil, any time that a major engine bearing is replaced.

The turbocharger increases power by compressing the fuel/air mixture before it enters the combustion chamber by using the exhaust gases passed through a turbine, the degree of utilization of boost is regulated by an assembly of the waste gate connected to a spring which, in turn allows part of the exhaust gases to bypass the turbine. Intake air which is compressed and being hot is first cooled by an intercooler that is usually positioned in front of the radiator with the aim of increasing the density of the air through cooling to boost the engine output. That means do not race or accelerate suddenly especially when the engine is cold, and do not stop the engine immediately you are through with tows, speeding or on a hilly terrain, give it some few minutes of idling after towing or speeding, 1-2 minutes depending on the driving condition. Further, the driving without an air cleaner is prohibited as the foreign particles can get into the intake system and damage severely the turbine and impeller wheels, with speeds varying between 20, 000 and 110, 000 rpm.

Plug all intake and exhaust ports and the oil inlet to prevent the entry of dirt and foreign matter while the turbocharger is removed.