my Toyota RAV4 XA50 (2019-2024) makes a whining noise when accelerating, why?

Solution

1. Preparation

• Gather tools: OBD-II scanner, socket set, multimeter, fluid inspection tools.
• Ensure the vehicle is parked on a level surface and the engine is cool.

2. Replace Serpentine Belt (if damaged)

• Sub-steps:
  1. Disconnect the negative battery terminal to prevent electrical shorts.
  2. Locate the serpentine belt tensioner and use a socket to relieve tension on the belt.
  3. Remove the old serpentine belt from the pulleys.
  4. Install the new serpentine belt following the routing diagram typically found on a sticker in the engine bay.
  5. Reapply tension with the tensioner and ensure the belt is seated correctly on all pulleys.

3. Check and Replace Transmission Fluid (if low or dirty)

• Sub-steps:
  1. Locate the transmission dipstick (if applicable) or drain plug.
  2. If checking fluid level, remove the dipstick and wipe it clean, then reinsert and check level.
  3. If fluid is low, remove the transmission drain plug and drain old fluid into a container.
  4. Replace with new fluid (consult owner’s manual for correct type and quantity).
  5. Reinstall the drain plug and ensure it is torqued to manufacturer specifications.

4. Inspect and Replace Alternator (if faulty)

• Sub-steps:
  1. Disconnect the battery again for safety.
  2. Remove the serpentine belt to access the alternator.
  3. Disconnect the electrical connectors from the alternator.
  4. Remove bolts securing the alternator to the mounting bracket.
  5. Install the new alternator, reattach connectors, and secure with bolts.
  6. Reinstall the serpentine belt and reconnect the battery.