Drivers of 2002-05 Mercury Sable and 2002-06 Ford Taurus models may come into your store with a complaint of a boom-type noise, a rough idle and/or a vibration that can be felt through the steering wheel.
According to Ford, the problems usually surface in temperatures above 80 degrees F,with the air conditioning on, and most likely are due to one or both of the electric cooling fans being out-of-balance.
Start the diagnosis by disconnecting the coolant temperature sensor connector and starting the engine, which will force the cooling fans to high speed.
If you hear the booming noise and/or feel a vibration, you're dealing with an out-of-balance condition.
To determine which fan is at fault, put your hand on the shroud at the point closest to where the fan assembly mounts to the radiator support.
If you feel an abnormal shake, replace the fan with an upgraded design. Order part No. 3F1Z-8C607-HA for the right-side fan; part No. 3F1Z-8C607-GA for the left-side fan.
"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].