GM Service Manual Online
For 1990-2009 cars only

LOSS OF ENGINE OIL PRESSURE ENGINE OIL COOLER

VEHICLES AFFECTED: All Model Years Trucks/Passenger Cars with 5.0L and 5.7L V-8 Engines and KC4 Engine Oil Coolers

Some vehicles equipped with 5.0L and 5.7L V8's and engine oil coolers (RPO KC4) may encounter a 'no engine oil pressure' after an oil change or hot soak. This condition may be caused by trapped air in the oil cooler assembly.

Performing the following steps should eliminate any additional occurrences:

1. Remove the engine oil filter.

2. Remove the cooler lines from the cooler adapter assembly.

3. Remove the two (2) cooler adapter to engine block attaching bolts.

4. Drill two (2) 1.6mm (1/16 in.) air bleed holes in the cooler adapter as shown in the attached illustration.

5. Clean adapter with a suitable solvent making sure all metal chips are removed.

6. Reinstall the adapter and torque the attaching bolts to 9.04 N.m (80 in. lbs.).

NOTICE: Replace the adapter seal and gasket using the appropriate part number assigned to the engine RPO.

7. Reinstall the cooler lines and oil filter.

8. Start engine and check for oil leaks.

Use most applicable Labour Operation from Canadian Labour Time Guide and Claim: .6 Hours


Object Number: 78191  Size: FS

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those 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 a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.