why does my BMW X3 F25 (2011-2018) have a high-pitched whine when accelerating

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface with the engine off.
• Disconnect the negative terminal of the battery for safety.

2. Inspect and Replace Serpentine Belt

• Sub-steps:
  1. Remove any covers obstructing access to the serpentine belt.
  2. Use a socket or wrench to release tension from the belt tensioner.
  3. Carefully remove the serpentine belt from the pulleys.
  4. Inspect the belt for cracks, fraying, or signs of wear; replace if necessary.
  5. Route the new belt according to the belt routing diagram and reapply tension.
• Tools Required: Socket set, belt tensioner tool, inspection light.

3. Inspect and Replace Tensioner and Idler Pulleys

• Sub-steps:
  1. Check the tensioner for proper spring action and bearing noise.
  2. Remove the tensioner and idler pulleys using a socket set.
  3. Inspect for any signs of wear or damage; replace if they feel loose or noisy.
  4. Install new pulleys and torque to the manufacturer's specifications.
• Tools Required: Socket set, torque wrench.

4. Check the Air Intake System

• Sub-steps:
  1. Inspect the air filter and intake hose for obstructions or leaks.
  2. Replace the air filter if it is dirty or clogged.
  3. Ensure all clamps and connections are tight and secure.
• Tools Required: Screwdriver, replacement air filter.