The Car Connection has reported that GM has found a problem with the supercharger on select 2009 – 2013 Cadillac CTS-Vs.
On affected vehicles, the supercharger may not perform as designed, resulting in contamination of the unit’s internal bearing shaft grease. When the problem is present, a rattle can be heard emanating from the engine at idle; slight acceleration above idle will cause it to go away.
If left uncorrected, contamination of the internal shaft bearing grease will accelerate into bearing failure, resulting in a loud squeal, then possible catastrophic engine damage or a no-start condition.
On affected vehicles, GM dealers will replace the supercharger at no charge.
For further information you can contact GM at 1-800-458-8006. You can also contact your local dealer with your VIN (Vehicle Identification Number) to determine if your vehicle is affected.