Engine - Oil Leaks

91pontiac03

Bulletin Number: 91-6-38
Reference Number: 136508
Publish Date: 4/91


Subject: ENGINE OIL LEAKS (DIAGNOSIS/APPLY NEW RTV SEALER AT FRONT AND REAR OF MANIFOLD)

Models
Affected: 1990-91 6000, SUNBIRD AND GRAND PRIX MODELS W/3.1L ENG.


Condition:

Oil leaks on the above engines may be misdiagnosed as head gasket failures. However, these leaks may be occurring at the front or rear of the intake manifold where it contacts the cylinder block.

Cause:

Leaks may be due to an insufficient quantity of RTV sealer (where the intake manifold, cylinder block and cylinder head meet) at the front or rear of the intake manifold.

Correction:

Use normal diagnostic measures to determine if the oil leak is at the front or rear of the intake manifold to cylinder case ridge. If a leak is found, use Service Manual repair procedures and clean RTV sealant from front and rear ridges on intake manifold and cylinder case. Apply new RTV sealer, P/N 1052917 (or equivalent) and reassemble intake manifold per Service Manual.





The sealing bead must run-up the cylinder head face approximately 3/16 of an inch at both ends of the front and rear cylinder block ridges. See Illustration.