Intake Manifold Gaskets - Revised
Bulletin 86-6-5Date Jan. '86
Ref. No 86-068-6
SUBJECT: INTAKE MANIFOLD GASKETS
MODELS AFFECTED: 1985 LESABRE AND ELECTRA ESTATE WAGONS AND RIVIERA 1986 REGAL AND LESABRE AND ELECTRA ESTATE WAGONS WITH 5.0L V-8 ENGINES (VIN CODE Y)
A mid-year change has been made in the intake manifold gasket. All 1985 and early 1986 models with 5.0L (VIN Code Y) engines used a gasket with an insulating sheath applied to the gasket in the area that contacts the intake manifold. This insulating material is dark orange in color.
LOSS OF COOLANT
There have been cases where the sheath in the area of the coolant passages has deteriorated which resulted in a leak. Most coolant leaks are external; however, there have been cases where coolant leaks have been internal. When investigating a loss of coolant, and a leak is not obvious, remove the intake manifold and examine the gasket for deterioration and evidence of an internal leak in the area of the coolant passages. If an internal leak is found, replacement of heads, blocks or intake manifolds is necessary.
REVISED SERVICE GASKETS
The service gaskets will, in the near future, be revised to delete the insulation sheath. When using one of the revised gaskets, it is essential that sealer, part no. 1050026 or equivalent be applied to both sides of the gasket where it contacts the cylinder head and the intake manifold.
Please revise your 1985 and 1986 Buick Chassis Service Manuals.