Bonneville V6-231 3.8L VIN 3 SFI (1988)
Oil Pressure Sender: All Technical Service Bulletins
Instruments - False High Oil Pressure Gage Readings
Bulletin Number:
88-6-12
Reference Number:
806401
Publish Date:
12/87
Subject:
FALSE HIGH OIL PRESSURE GAGE READINGS
Models
1988 VEHICLES EQUIPPED WITH 3.8L LG3
Affected:
(VIN CODE 3), 3800 LN3 (VIN CODE C) V-6 ENGINES
Figure 1
Some of the above listed vehicles may exhibit false high oil pressure gage readings during normal engine operation.
This condition may be due to a loss of ground to the oil pressure switch mounted in the oil filter adapter (refer to Figure 1). The condition may be
confirmed and corrected by the following procedure:
1.
Verify that the oil pressure gage is reading high.
NOTICE:
Normal engine oil pressure should be approximately 20 psi at idle in drive, with the engine at operating temperature; and
approximately 45 psi at 2000 E.R.P.M. in park with the engine at operating temperature.
2.
Ground the base of the oil pressure sensor to the negative battery terminal or a known good chassis ground.
3.
If procedure Step 2 causes a correction in the pressure gage reading, remove and discard the four (4) bolts that attach the oil filter adapter to the
front cover. Install a new oil filter adapter gasket, Part Number 25529916 and replace the original bolts with four (4) bolts, Part Number
25534181. Torque the new bolts to 17 N-m (12.5 ft.lbs.).
4.
Verify that the oil pressure gage is reading correctly and inspect the oil filter adapter gasket area for leaks.
If the above does not cause a change in the pressure gage reading, or if the new reading is below recommended minimum oil pressures; follow the
normal service diagnostic procedure for the engine oiling system.