| Subject: | Squeal from Engine Compartment (Install Mounting Sleeves to A/C Compressor) | 
| Models: | 2007-2008 Chevrolet Caprice, Lumina (Export) | 
| with V6 Engine | 
Some customers may comment on a constant squeal noise coming from the engine compartment, particularly after a cold start, at idle and/or slow acceleration.
The squeal noise should not be confused with a start up "chirp" noise which only occurs during engine cranking.
In addition, the noise is not influenced by the A/C being on or off or alternator load (i.e. high electrical load = high accessory drive load).
It is possible for the A/C compressor pulley to be out of alignment by approximately ½ a belt rib (2mm) relative to the engine crankshaft accessory drive belt pulley.
This means, that on checking with a laser device (refer to "Note" at the end of this bulletin), the A/C compressor pulley will be forward, relative to the crankshaft accessory drive belt pulley. This is caused by excessive clearance between the compressor mounting holes and bolts.
As an interim solution, A/C compressor mounting sleeves (refer to graphic above) have been developed for implementation in production as well as a field fix.
ISOVIN  | Build Date  | 
|---|---|
6G1EK52B48L101141  | 11/09/07  | 
Important: 
   •  It is not necessary to remove the A/C compressor plumbing and wiring as part of this procedure.    •  Refer to Drive Belt Squeal, Chirping and Whine Diagnosis within SI (Global Connect - document #1990868). 
After verifying that the vehicle has the condition described above, install mounting sleeves to the A/C compressor using the following procedure.
If required, it may be helpful to refer to the following section is SI (Global Connect) -- Air Conditioning Compressor Replacement-3.6L Engine (document # 1977379).
| 4.1. | Sit the sleeve insert over the bolt hole. | 
| 4.2. | Push the sleeve insert into the bolt hole (a few gentle taps may be required). | 
| 4.3. | Ensure the sleeve insert is fully seated so that it is not protruding above the bracket mounting face. | 
Note: A "Drivealign Laser Tool" from Gates Australia (p/n 91006), or any similar type of laser type belt alignment checking tool, is advantageous for conducting quick and accurate alignment of the accessory drive belt system.
Part Number  | Description  | Qty  | 
|---|---|---|
92221235  | Sleeve  | 2  | 
For vehicles repaired under warranty, use:
Labor Operation  | Description  | Labor Time  | 
|---|---|---|
D4440  | A/C Compressor - R&R  | 0.7 hr  |