Engine - Exhaust Smoke After Extended Idle

87buick14

Bulletin: 86-6F-2

Date: Dec., 87

Ref. No. 86-213-6F

Corp. Ref. No. 636008R
SUBJECT: 2.5L L4 ENGINE EXHAUST SMOKE AFTER EXTENDED IDLE


MODELS AFFECTED: 1986 CENTURYS WITH THE LR8 L4 ENGINE (VIN CODE R) 1986 SOMERSETS/SKYLARKS WITH THE L68 2.5L L4 ENGINE (VIN CODE U)
A condition of blue exhaust tailpipe smoke may occur during drive away, after an extended idle, on 1986 Buicks with a 2.5L engine.

This condition is the result of excessive oil accumulation on the exhaust valve stems and only occurs after a prolonged idle period followed by a rapid application of the throttle.

To repair this condition, replace all the exhaust valve springs with spring, Part Number 3735381, and shield, Part Number 10007818.

As in any service procedure, diagnostics are the key to an effective repair. Verification that existing intake valve seals are present and correctly installed and that casting porosity is not present, should precede this procedure.

WARRANTY INFORMATION

Use applicable labor operation number and labor time.