Ninety-Eight V6-3.8L VIN K (1995)
Intake Manifold: Customer Interest
Engine - Coolant Leak Near Belt Tensioner Assembly
FILE IN SECTION: 6 - Engine
BULLETIN NO.: 57-61-05
DATE: June, 1995
SUBJECT:
Coolant Leak Near Belt Tensioner Assembly (Replace O-rings on Heater Coolant Bypass Inlet Pipe Assembly)
MODELS:
1995 Buick Park Avenue, Riviera
1995 Oldsmobile Eighty Eight, Ninety Eight
1995 Pontiac Bonneville
with 3800 Series II Engine (VIN K - RPO L36)
Built beginning November 11, 1994 through November 16, 1994.
CONDITION
Some owners may comment about an engine coolant leak which may be traceable to the vicinity of the belt tensioner assembly and near the lower intake
manifold.
CAUSE
On some engines, the lower intake manifold may have an oversize hole where the heater coolant bypass inlet pipe attaches. Refer to the illustration. An
oversize hole may not provide sufficient O-ring compression and result in a coolant leak at this joint.
CORRECTION
Replace the production O-ring on the heater coolant bypass inlet pipe with an oversize service O-ring that will compensate for the larger hole. The heater
coolant bypass inlet pipe has two O-rings. The production O-rings will appear orange/black in color after being in service, however, they will appear as a
solid orange color when new. The service O-ring is purple in color. Remove both production orange/black O-rings from the inlet pipe. Install a service
purple O-ring on the end of the pipe that attaches to the lower intake manifold. Install a new production orange O-ring on the opposite end of the pipe.
Refer to the illustration.
