This bulletin applies to 2014-2016 Cadillac CTS-V Sport and XTS vehicles equipped with the LF3 Twin Turbocharged engine. A rattle noise at the turbocharger may be evident when cold, at idle. There is a revised part available for this concern.
The new part has a revised spring for the wastegate to limit movement when cold. The new part numbers are 12666538 (LH) and 12666539 (RH) for CTS-V Sport and 12666540 (both RH and LH) for the XTS.