G 20 Van V6-262 4.3L VIN Z (1993)
Oil Pressure Gauge: Customer Interest
Engine - High Oil Pressure Reading at Start-Up
Number: 93-60-6A
Section: 6A
Date: NOV. 1992
Corporate Bulletin No.: 268306
ASE No.: A1, A8
Subject:
HIGH OIL PRESSURE READING AT START-UP
Model and Year:
1992-93 LIGHT DUTY TRUCKS WITH 4.3L, 5.0L, AND 5.7L ENGINES
Some 1992 and 1993 Chevrolet Light Duty Trucks with oil pressure gauges built after 6/15/92 may exhibit high oil pressure readings at start up,
especially when cold.
Engines produced after 6/15/92 were built with an enhanced oil pump capable of producing approximately 10 psi more pressure than the previous pump.
This may cause the gauge to temporarily read as high as 60 psi during start up. The length of time the oil pressure stays high will depend on oil viscosity,
engine temperature, and ambient temperature.
This condition will not cause any ill effects on the engine or gauge and unless there are other symptoms to indicate an oil pressure or gauge problem such
as very low pressure after warm up, rapid fluctuation, engine noise etc. no repairs should be attempted. Replacing the oil pump or gauge system parts will
not be effective.
Build date of the engine can be verified by the engine code. The location of this code is illustrated in section OA of the appropriate service manual. The
engine code is 8 positions long with an alpha plant designator in the first position, followed in the next four positions by the month and day; for example
T0615xxx would indicate that this engine was built in Tonawanda on June 15th and, therefore, has the enhanced oil pump. The plant code is insignificant
because all 4.3L, 5.0L, and 5.7L plants began using the enhanced oil pump on the same day.
