Some 2010 Dodge Nitro and Jeep Liberty, Grand Cherokee and Commander models with 3.7-liter engines may emit a chirping sound from the drive belt when the steering wheel is at full lock and the engine idling.
According to Chrysler, the belt noise usually stops once the engine comes off idle and is most likely due to a defective automatic belt tensioner. Installing a new-design tensioner, part # 53030958AE, may help eliminate the ruckus.
To find out for sure, open the hood and look at the part number on the top/front portion of the existing tensioner. If the part number is 53030958AE, the new-design tensioner is already in the vehicle; continue troubleshooting until the source of the belt noise is found. If the part number isn't 53030958AE, proceed to install the new belt tensioner.