Some owners of 2014-2016 turbocharged Cadillac CTS Sedan, XTS or ATS-V vehicles may comment on a brief rattle or tick when revving the engine when the transmission is in park or neutral.
The same noise may be heard at the beginning or end of a vehicle acceleration while in drive. The noise may be a normal characteristic of the turbo wastegate, or may be caused by loose converter bracket nuts/brackets.
Inspect all M8 nuts that secure the catalytic converters to the exhaust bracket, If the nuts are loose, replace them with new torque-prevailing nuts P/N 11546441. If the nuts are not loose and are torqued correctly, do not replace the turbocharger assembly in an effort to eliminate the brief rattle/tick.
