Info - Correct Oil Viscosity and Oil Filter Usage for the Duramax 6600 Diesel Engine (RPO LB7)

This bulletin is being revised to add the AC Delco oil filter part number and add the 2002 Model Year. Please discard Corporate Bulletin Number 00-06-01-025 (Section 06 -- Engine/Propulsion System).

Important: The Duramax 6600 diesel engine can produce oil pressures over 690 kPa (100 psi) during a cold start condition and the oil pressure gauge may remain near 552 kPa (80 psi) while driving. Because of these oil pressures, it is important that the correct oil filter is used and torqued properly and the proper oil viscosity is used for the ambient temperatures.

The correct oil filter for use on the Duramax 6600 engine is the AC PF2232 or the production oil filter, GM P/N 97214983. This filter was designed specifically for use on the Duramax 6600 engine and incorporates improved filtering capabilities as well as an integral oil pressure relief valve. The oil filter should be torqued to 24 N·m (18 lb ft) to prevent leaks under high pressure conditions.

SAE 5W-40 viscosity oil designated as API CH-4 or CG-4 should be used if the ambient temperature falls below -18°C (0°F) to prevent excessive oil pressure on a cold start. Refer to the Owner's Manual diesel supplement for additional information on proper oil usage for other operating conditions.

Parts are currently available from GMSPO.