Some 2007-10 General Motors Co. cars and light trucks with 3.5- or 3.9-liter engines may develop a squealing noise on start-up. GM says the noise is often accompanied by an obvious engine vibration, and is likely due to the outer ring of the crankshaft balancer slipping on the center hub.
New-design crank balancers are now available to address the issues. Check with a dealer for the part number for your specific application.
Vehicles that are prone to the condition are 2007 Buick Rendezvous and Chevy Monte Carlos; 2007-08 Buick Terrazas; 2007-09 Chevy Uplanders and Pontiac Montana SV6s; 2007-10 Chevy Malibus and Pontiac G6s; and 2007-11 Chevy Impalas.
"Factory Fixes" is written by Jim DePalma, a 30-year veteran of the auto repair business who has served stints as a service manager, parts manager and ASE-certified technician. His column provides vehicle manufacturers' authentic factory technical service bulletins (TSBs) that have been condensed for easier reading. Mr. DePalma advises that techs always check with a dealer or repair information system for the latest revisions before starting to work on a vehicle. He can be reached via e-mail at [email protected].