Oil Pressure Gauge - Erratic Reading Concerns
File In Section: 6 - EngineBulletin No. 47-61-49
Date: December, 1994
Subject:
Oil Pressure Gauge Reading Concerns (Replace Oil Pressure Sending Unit)
Models:
1991-94 Chevrolet and GMC Truck C/K, S/T, P Models, M/L, G Vans
1991-92 Oldsmobile Bravada with 2.2L, 4.3L, 5.0L, 5.7L, 7.4L Engines (VINs 4, Z, H, K, N - RPOs LN2, LB4, L03, L05, L19)
CONDITION
Some owners may comment on one or all of the following conditions:
^ High oil pressure when starting engine cold.
^ Low oil pressure when engine is at idle hot.
^ Erratic gauge readings.
CAUSE
Oil pressure sending unit was not optimally calibrated for all operating conditions.
CORRECTION
If actual oil pressures are within tolerances listed in Section 6A of the Service Manual, and gauge circuit electrical diagnostics in Section SC of the Service Manual do not uncover the source of the problem, an improved oil pressure sending unit should be installed.
Parts Information
DESCRIPTION PART NUMBER
Oil Pressure Sending Unit 12553175
Parts are currently available from GMSPO.
Warranty Information
For vehicles repaired under warranty, use:
LABOR OPERATION LABOR TIME
N222O Use published labor operation and time.