High pitch noise from the front car, especially when cold start.

1. Troubleshooting:
   • Use stethoscope to touch each pully to find the loudest part.
     • 
   • remove the belt, move pully side to side to see if there’s any play. Water pump and idler pully shouldn’t have any significant play to it.
2. Caution: perform the check and replacement when the engine is cold. The water pump could be very hot after the car been running for a while.
3. Tools:
   • Serpentine belt bent tool.
     • https://www.amazon.com/dp/B06X3VZNDD?ref=ppx_yo2ov_dt_b_fed_asin_title
     • 
   • Serpentine belt
     • OEM PN:68495977AA
     • My purchase: Gates Micro-V Serpentine Belt K060820(https://www.autozone.com/featured-parts/duralast-tensioners-and-gates-belts/p/gates-micro-v-serpentine-belt-k060820/1415905_0_0)
   • Idler pully
     • OEM PN:4627851AA
     • My purchase: (https://www.americanmuscle.com/challenger-serpentine-belt-idler-pulley-bpa03856.html)
4. Steps
   • Remove shaker hood by removing the 4 bolts near corners.
   • loosen the clamp of air intake tube near the engine air filter and engine.
   • Remove electrical connector of the intake temp.
   • Remove the intake tube (mine comes with resonator)
   • Put the serpentine bent tool to the tensioner. rotate counterclockwise to loosen the tension on the belt.
     • 
   • Remove the belt.
   • Visually check the belt to see if there is any crack by bending it backwards.
   • Remove the bolt on the Idler pully. Remove the Idler pully.
   • Put on the new Idler pully, put on bolt, torque to 21lb-ft.
   • put on the belt, follow the diagram below. Make the threads align with the pully.
   • Put back the intake tube, and connect the intake sensor temp connector.
   • Run the car. check the belt to see if there’s any misalignment, check each pully to see if there’s movement from left to right.
   • put back the shaker hood.