This preliminary information communication provides information to the technician on how to diagnose and...

Bulletin number

PIP-5401

Component

Engine

Summary

This preliminary information communication provides information to the technician on how to diagnose and repair a vehicle with engine regular production option code lgx when it has a hollow knock or tap noise coming from the engine compartment. With the vehicle warmed up to 98c or 208f determine if the noise is present. If the noise is present pump the brakes 3-5 times to see if the noise goes away, noise will return a short time later. If the noise goes away when applying the brakes do not attempt to repair this condition. Engineering is working with the pump supplier and calibrations to attempt to improve this situation. If the noise is still there proceed with service information diagnostics for lower engine noise.

Owners of these vehicles have filed 28 complaints in the engine category.