Loose Bracket Nuts Causes Cadillac Problems

Some owners of 2014-2016 Cadillac CTS or XTS vehicles equipped with a 3.6L turbocharged engine may comment about a brief rattle or tick when revving the engine when the transmission is in park or neutral. The same rattle can sometimes be heard at the beginning or end of acceleration while in drive. This condition may be caused by loose converter bracket nuts or it may be a normal characteristic of the turbo wastegate.

Information courtesy of Mitchell 1

Mike Mavrigian

Jan. 11, 2023

Check the nut tightness where the exhaust connects to the bracket.

Also, check the nuts where the bracket secures to the bellhousing.
Photo Credit: Mitchell 1

Inspect the M8 nuts that secure the catalytic converters to the exhaust bracket. If the nuts are loose, it is necessary to replace them with new torque prevailing nuts P/N 11546441. If the nuts are found to be torqued correctly, do not replace the turbo assembly in an effort to eliminate this brief rattle.

About the Author

Information courtesy of Mitchell 1

Information for Technical Service Bulletins comes from ProDemand, Mitchell 1's auto repair information software for domestic and import vehicles. Headquartered in San Diego, Mitchell 1 has provided quality repair information solutions to the automotive industry since 1918.

Mike Mavrigian

Motor Age Editor

Mike Mavrigian has written thousands of automotive technical magazine articles involving a variety of specialties, from engine building to wheel alignment, and has authored more than a dozen books that crisscross the automotive spectrum. Mike operates Birchwood Automotive, an Ohio shop that builds custom engines and performs vintage vehicle restorations. The shop also features a professional photo studio to document projects and to create images for articles and books.