Owners of 2004-2011 Cadillac STS, 2004-2015 CTS SRX and 2013-2015 ATS XTS vehicles equipped with a 3.6L engine may comment about an engine misfire and check engine light only on deceleration.
Owners of 2004-2011 Cadillac STS, 2004-2015 CTS SRX and 2013-2015 ATS XTS vehicles equipped with a 3.6L engine may comment about an engine misfire and check engine light only on deceleration.
This may be the result of debris in the serpentine belt or balancer pulley, causing a jump and false misfire. Another possible cause is worn engine mounts which may cause a ground-out and false misfire. Note: Do not confuse this with normal roughness and a few random misfire counts that are normal on these engines at the same speeds in park or neutral.
Remove the accessory drive belt and drive or brake-stall at the signature rpm of 1400 to 1800 rpm. If the concern is gone, inspect for debris in the serpentine belt or pulleys that may cause the jump/false misfires. Another inspection: use an engine lift to unload the engine mounts and brake stall at the signature rpm. If the concern is gone, inspect for a ground concern with the mounts.
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 has written thousands of automotive technical magazine articles involving a variety ofspecialties, 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.
Sign up for Vehicle Service Pros eNewsletters
Voice Your Opinion!
To join the conversation, and become an exclusive member of Vehicle Service Pros, create an account today!
