Some 2009 Mazda Tribute vehicles equipped with the 2.5L engine build from Oct. 27, 2008, to Nov. 28, 2008, may exhibit an accessory drive related high-pitched whine/whistle noise during a cold start.
The noise may be caused by the smooth idler pulley. This noise will be most evident between 1,100 to 1,500 rpm and may be more noticeable on engine deceleration from 1,500 rpm.
If the problem is verified, simply replace the smooth idler pulley. Refer to workshop manual Section 01-10b-ACCESSORY DRIVE BELT IDLER PULLEY REMOVAL/INSTALLATION – 2.5L.