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Drive Belt Chirp Noise - Potential Alignment and Belt Issues - keywords accessory adjustment bracket engine idler information mechanical pulley repeat squeak squeal

Subject:Drive Belt Chirp Noise - Potential Alignment and Belt Issues

Models:2004-2006 Chevrolet Colorado
2004-2006 GMC Canyon
2006 Hummer H3



The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:

On rare occasions, a belt chirp or squeak noise may be encountered at random conditions. This noise may the result of a misaligned idler bracket and pulley, misaligned power steering pump pulley, or serpentine belt material contamination.

Recommendation/Instructions:

If the SI diagnostics do not isolate a cause for this concern, the following information may help:

  1. If the vehicle is equipped with air conditioning and was manufactured before 4/26/2005, replace the Idler Pulley Bracket using Part Number 12590963. Vehicles manufactured on 4/26/2005 or later were manufactured with this updated bracket.
  2. Inspect the power steering pump pulley to shaft alignment. If the power steering pump pulley is not flush with the power steering pump pulley, adjust the pulley to make it flush with the shaft. Typically, when this is an issue, the pulley will be pressed on around 2 mm past the end of the shaft.
  3. Clean all pulleys and replace the serpentine belt with one of the following part numbers (or any superseding part numbers). This should address any coolant contamination that may have occurred during vehicle manufacturing.

Parts Information:

Part Number

Description

12593777

Without Air Conditioning

12593776

With Air Conditioning

Please follow this diagnostic or repair 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.