20NA161
Service Bulletin Details
Public Details for: 20NA161
This informational bulletin advises the technician to check for a possible stuck oil pressure relief valve.
Models from 2020
2020 CHEVROLET EXPRESS |
2020 GMC SAVANA |
Models from 2019
Bulletin No.: Service Bulletin Date: 20-NA-161 December, 2020 INFORMATION Subject: Brand: Chevrolet Information on Engine Low Oil Pressure Indicator on the Driver Information Center (DIC) - DTC P0521 Set Model: to Express 2020 3500/4500 Medium Duty (LCF) 2019 Silverado 2500/3500 GMC Model Year: from 2019 2019 Suburban 2019 Savana 2020 Sierra 2500/3500 2019 Date Breakpoint: from to SOP August 28, 2019 Engine: Transmission: 6.0L (L96 LC8) - Involved Region or Country North America, Middle East, Iraq, Israel, Palestine, Chile (West), Peru (West), Thailand (ASEAN) Condition Some customers may comment on one or more of the following conditions: • MIL is illuminated. • Oil Pressure Indicator on. Some customers may also comment that the MIL illuminates and then turns off. Some technicians may find DTC P0521 (Engine Oil Pressure Sensor Performance) active or stored in history in the Engine Control Module (ECM). This condition may be caused by a sticking oil pressure relief valve within the oil pump assembly. Cause ⇒ If vehicle was built after the breakpoint date, follow service information for the condition noted. It’s not necessary to follow the steps below for this cause. If you encounter a vehicle with the above DTC or conditions and before replacing any parts, it will be necessary to follow the steps below to determine what failure mode may exist and what the correct repair procedure is: 1. Remove the oil level indicator and confirm the oil level is at the full mark and not overfilled. 2. With a manual oil pressure gauge, bring the engine to normal operating temperature. ⇒ Verify the oil pressure is within specification. Refer to Engine Mechanical Specification (RPO L96 VIN G) in SI for proper specification. Correction • If engine oil pressure is less than normal, replace the engine oil filter and retest. • If engine oil pressure is still low, it will be necessary to inspect the #1 main bearing for any damage. ⇒ If the #1 main bearing is not damaged, then it will be necessary to replace the engine oil pump only. ⇒ If the #1 main bearing is damaged but not spun it will be necessary to replace the crankshaft, main bearings, rod bearings and the engine oil pump. ⇒ If the #1 main bearing was spun it will be necessary to replace the engine assembly. 3. When the applicable repair is complete road test vehicle to ensure engine is operating as designed. Copyright 2020 General Motors LLC. All Rights Reserved. Page 2 December, 2020 Parts Information Causal Part Description Part Number Qty X PUMP, OIL 12696357 1 N/A ENGINE, GASOLINE (SERV NEW) L96 19256594 1 ENGINE, GASOLINE (SERV NEW) LC8 12642269 1 N/A N/A N/A N/A BEARING KIT, CR/SHF (#1,2,4, 5) (STD) 89017571 4 BEARING KIT, CONN ROD (STD) 89017573 8 N/A GASKET, OIL PAN 12612350 1 N/A SEAL, O/PMP SUC PIPE (0-RING) 12584922 1 N/A Description N/A 12685656 N/A Causal Part N/A CRANKSHAFT, (CROSS DRILLED CRANK) Bulletin No.: 20-NA-161 1 N/A N/A N/A Part Number Qty HOUSING, CR/ SHF RR OIL SEAL 12639250 1 GASKET, CR/ SHF RR OIL SEAL HSG 12639249 1 BOLT, CR/SHF BALR (M16x2.0x103) 12557840 1 STUD, CR/SHF BRG CAP (HFH, M10x2x23) 12560273 10 BOLT, CR/SHF BRG CAP (SIDE) (SHORT) (M8x1.25x11) 12556127 10 BOLT, CR/SHF BRG CAP (M10x2x102.5) 12560272 10 GASKET, ENG FRT CVR 12633904 1 Warranty Information Note: Only use the Labor Operation number that coincides with the repair performed. For vehicles repaired under warranty, use: Labor Operation Description 4066070 Oil Pump Replacement 4067490 Engine Replacement 4066750 Crankshaft Replacement Version 1 Modified Released November 30, 2020 GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information. Labor Time Use the Published Labor Operations Time WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION