DISC 7D8434 - Caterpillar

Periodic inspection and cleaning are recommended for the turbocharger. Fouling of the turbine wheels can contribute to loss of engine power and overall loss of engine efficiency.If the turbocharger fails during engine operation, damage to the turbocharger compressor wheel and/or to the engine may occur. Damage to the turbocharger compressor wheel could allow parts from the compressor wheel to enter an engine cylinder. This condition can damage the pistons, the valves, and the cylinder head.
Turbocharger bearing failures can cause large quantities of oil to enter the air inlet and exhaust systems. Loss of engine lubricant can result in serious engine damage.Minor leakage of a turbocharger housing under extended low idle operation should not cause problems as long as a turbocharger bearing failure has not occurred.When a turbocharger bearing failure is accompanied by a significant engine performance loss (exhaust smoke or engine rpm up at no load), do not continue engine operation until the turbocharger is repaired or replaced.
An inspection of the turbocharger can minimize unscheduled downtime. Also, the chance for potential damage to other engine parts is reduced.Note: Turbocharger components require clearances that are precise. The turbocharger cartridge must be balanced due to high rpm.The following conditions can cause the turbocharger to be out-of-balance:
The buildup of deposits
Chipping and/or flaking of depositsIf the turbocharger must be removed for inspection, use caution. Do not break deposits from the turbine wheel. Do not attempt to clean the turbine wheel. For information regarding removal and installation, see the Disassembly and Assembly manual or consult your Cat dealer. For information about repair of the turbocharger or about replacement of the turbocharger, consult your Cat dealer.
Remove the exhaust outlet piping and remove the air inlet piping from the turbocharger. Visually inspect the piping for the presence of oil.
Turn the compressor wheel and the turbine wheel by hand. The assembly should turn freely. Inspect the compressor wheel and the turbine wheel for contact with the turbocharger housing. There should not be any visible signs of contact between the turbine wheel or compressor wheel and the turbocharger housing. If there is any indication of contact between the rotating turbine wheel or the compressor wheel and the turbocharger housing, the turbocharger should be reconditioned.
Check the compressor wheel for cleanliness. If only the inlet side of the wheel is dirty, dirt and/or moisture is passing through the air filtering system. If oil is found only on the back side of the wheel, there is a possibility of a failed turbocharger oil seal. The presence of oil may be the result of extended engine operation at low idle. The presence of oil may also result from restriction of the inlet air (plugged air filters). This causes oil to leak past the seal for the turbocharger compressor.If oil is found on the compressor wheel, the source of the oil can be the fuel compressor. If oil is found at the air inlet, the source of oil can be the PCV system.Note: Deposits of ash and silicone can accumulate on the