Models affected: 2004-’05 Cadillac CTS, SRX; and 2005 Cadillac STS — with 3.6L engine and without heavy-duty cooling.

Some customers may comment on a whine, whistle or ringing-type noise from the front of the engine that increases in intensity as engine rpm increases. This noise is most audible standing in front of the vehicle with the hood opened.

If the noise fades into the ambient engine noise by 2,000 rpm, refer to PIP3453 in the Service Information (SI) for camshaft drive chain noise.

This condition may be caused by the harmonic balancer.

Important: If the vehicle is equipped with the V03/V92 Heavy Duty Cooling package, DO NOT replace the six-spoke design crankshaft harmonic balancer. Continue with routine diagnosis to isolate the noise.

Inspect the crankshaft harmonic balancer. If the vehicle was built with the three-spoke design crankshaft harmonic balancer, replace the harmonic balancer with P/N 12597654. Refer to Crankshaft Balancer Removal, Cleaning and Inspection and Installation in SI.

If the vehicle was built with the new design six-spoke crankshaft harmonic balancer, do not replace it. Continue on with routine diagnosis to isolate the noise.

Courtesy of General Motors.