Here is a bulletin or two for you all?
#05-06-01-013C: Whine, Whistle, Ringing Type Noise Heard From Front of Engine (Replace Crankshaft Harmonic Balancer) - (Aug 16, 2006)
Subject: Whine, Whistle, Ringing Type Noise Heard From Front of Engine (Replace Crankshaft Harmonic Balancer)
Models: 2004-2005 Cadillac CTS, SRX
2005 Cadillac STS
with 3.6L Engine (VIN 7 -- RPO LY7) and
without Heavy Duty Cooling (RPO V03/V92)
This bulletin is being revised to add additional information in the Condition statement. Please discard Corporate Bulletin Number 05-06-01-013B (Section 06 - Engine Mechanical).
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.
A very faint engine whine noise heard at speeds of 0-48 km/h (0-30 mph) at 1000-2500 RPM may be caused by the primary camshaft drive chain. Refer to Corporate Bulletin Number 06-06-01-018 for more information about this type of noise. Cause
This condition may be caused may 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.
Refer to the above graphic illustration and inspect the crankshaft harmonic balancer for design type. After the inspection, if the vehicle was built with three spoke (1) design crankshaft harmonic balancer, replace the harmonic balancer with P/N 12597654. Refer to Crankshaft Balancer Removal, Cleaning and Inspection, and Installation in SI.
Refer to the above graphic illustration and if the vehicle was built with the NEW DESIGN six spoke (1) crankshaft harmonic balancer, DO NOT replace it. Continue on with routine diagnosis to isolate the noise.
Balancer, Crankshaft Harmonic
#PIP3381: Engine Mechanical Noise Described as a Valvetrain Tick or Chatter Coming from the Cylinder Head - keywords 3.6L camshaft LY7 - (Mar 31, 2005)
Subject: Engine Mechanical Noise Described as a Valvetrain Tick or Chatter Coming from the Cylinder Head
Models: 2004 Buick Rendezvous
2004 Cadillac CTS
2004 Cadillac SRX
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in the PI.
Engine mechanical noise described as a valvetrain tick or chatter coming from the cylinder head.
Engineering investigation on return engines shows the roller finger followers causing the noise. The Camshafts should be inspected for obvious damage and replaced if showing damage. In most cases the camshafts were ok. After replacing the roller finger followers, start the engine, but do not let the engine idle for any length of time. Idling or extended idling conditions may cause the new roller finger followers to fail. Also use care in running the engine. Vary the engine RPM, and don't over rev the engine. The vehicle needs to be driven for 25 miles minimum at highway or expressway conditions
#PI01781: 3.6L LY7 Engine - Rattle Noise Coming from the Engine - kw bushing intake manifold mechanical performance valve - (Feb 24, 2004)
Subject: 3.6L LY7 Engine - Rattle Noise Coming from the Engine
When servicing the vehicle with the VIN you entered, the following diagnosis might be helpful if the vehicle exhibits the described symptoms.
The concern is a rattle noise coming from the engine.
Disconnecting the intake manifold tuning valve could eliminate the rattle noise. If the replacement of the intake manifold tuning valve did not change the noise, the correction is to replace the upper intake manifold because the bushing for the intake manifold tuning valve was missing.
Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed. If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance. This diagnostic approach was developed for the vehicle with the VIN you entered and should not be automatically be used for other vehicles with similar symptoms.
(2004 Cadillac CTS) and 2004 Cadillac SRX)
Monday, August 10th, 2009 AT 10:00 PM