Owners of 1996-2004 Chevy Astro and GMC Safari vans may complain of a booming sound that resonates into the passenger compartment during engine warm-up. The most likely cause of the noise, reports GM, is the unique frequencies that set up in the exhaust system as it expands and heats up during the warm-up cycle.
Installing a specially designed exhaust dampener assembly, part No. 15047524, onto the catalytic converter pipe should eliminate the condition. In addition to the dampener, you'll need three 1/16" thick flat washers and a lock washer.
"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 email at [email protected].