BENDIX TCH-001-027 User Manual

Technical Bulletin

Bulletin No: PRO-01-27 Effective Date: 9/15/84 Cancels: NA Page: 1 of 1

Subject:

Bendix has learned through extensive laboratory testing and fleet surveys that multiviscosity (15W40) oils can
cause compressor inlet carbonization, which results in slow air build-up in the compressor load cycle.
Carbonization attributable to the use of multiviscosity oil is generally manifested by a soft sticky deposit that
causes inlet valve and/or unloader malfunction. Commercially available multiviscosity oils vary considerably in
their tendency to form these deposits. Heat build-up in the inlet cavity due to turbocharging aggravates the
tendency to form deposits with multiviscosity oils. Single viscosity oils such as SAE 30 or 40, however, have been
shown not to form deposits of the type described.

When an increase in the incidence of compressor carbonization is encountered, an alternative oil type should be
considered along with an investigation of the compressor cooling and induction systems.

ENGINE OIL AND COMPRESSOR INLET CARBONIZATION