To obtain good service life and efficient performance of the turbocharger, always observe good maintenance practices. Air and oil filtration – are the most important areas for maintaining the turbocharger. The majority of inoperative turbochargers are caused by:
1. Dirt in the oil
2. Sludged oil
3. Oil lag/lack of good oil flow
4. Foreign objects or material entering the
5. Plugged or restricted air inlet system
6. Contaminated oil or use of improperly formulated oil
1. Dirt in the Oil
Dirt or other contaminants introduced into the turbocharger bearing system create wear, primarily on journal bearing surfaces and the bearing center housing bore surface. Turbocharger and engine performance can quickly deteriorate, resulting in engine power loss, excessive smoke, noise, or turbocharger oil seal leaks.
2. Sludged Oil
Required oil change intervals must be adhered to so that sludge does not build up and affect turbocharger operation. This buildup can slow shaft rotation, inhibit oil drain back, and cause oil leakage past compressor and turbine seals by unseating turbine shaft seals.
Turbocharger bearing damage may occur if the oil delay exceeds 30 seconds, or much sooner if the engine is allowed to accelerate beyond low idle rpm.
3. Lack of Oil Flow
During normal engine starting, adequate oil is supplied to the turbocharger bearings. However, a turbocharger is more sensitive to a limited oil supply than an engine because
of the high rotational speed of the shaft. Low oil pressure and/or flow lag during engine starting can have destructive effects on the turbocharger bearings. Use care when starting the engine after oil/filter change or extended storage. During normal engine starting, this should not be a concern.
4. Foreign Objects or Material Entering the Turbocharger
Dust, sand or dirt, etc., entering the turbocharger com pressor housing from a leaky air inlet system or inadequate air cleaner can erode the compressor wheel blades and significantly reduce turbocharger and engine performance. Uneven wear of compressor wheel blades can cause shaft motion (imbalance) that will eventually damage the turbo charger shaft bearings. Entrance of large or heavy objects (bolts, nuts, rocks, tools, etc.) will completely destroy the turbocharger, possibly causing severe damage to the engine.
5. Plugged or Restricted Air Inlet System
Plugged or restricted air inlet systems are the result of poor maintenance procedures and will reduce air flow rate at the compressor air inlet. This may cause:
A. Loss of turbocharger performance
B. High exhaust and engine temperature
C. Black smoke
D. Compressor and/or turbine oil seal leaks
E. Compressor surge
Proper servicing of the air inlet system can prevent and correct the above conditions.
6. Contaminated Oil or Use of Improperly Formulated Oil
Proper care should be given when oil is added, that it meets the Detroit Diesel requirements and that the source of the oil is known.