my BMW X3 F25 (2011-2018) makes a loud whining noise during acceleration

Solution

1. Preparation

• Tools Required: Jack stands, wrench set, fluid catch pan, OBD-II scanner, flashlight.
• Safety Warnings: Ensure the vehicle is on a level surface. Use jack stands to support the vehicle when working underneath.

2. Inspect and Replace Worn Belts

• Step 1: Remove the engine cover (if applicable) by unscrewing any retaining bolts.
• Step 2: Visually inspect both the serpentine and timing belts for signs of wear or damage.
• Step 3: If damaged, loosen the tensioner using a wrench and remove the worn belt.
• Step 4: Install a new belt by routing it according to the belt routing diagram and ensure correct tension is applied.

3. Address Fluid Levels

• Step 1: Check the transmission fluid level using the dipstick or fill plug.
• Step 2: If low, drain old fluid into a pan, and refill with the manufacturer-recommended transmission fluid (check the owner’s manual for specifications).
• Step 3: For the power steering fluid, remove the cap and top off with the appropriate fluid, ensuring no leaks are present.

4. Inspect and Service Differential

• Step 1: Safely lift the rear of the vehicle and support it with jack stands.
• Step 2: Remove the differential cover bolts and drain the fluid into a pan.
• Step 3: Inspect the gears for wear or damage. Clean the mating surfaces and install a new gasket.
• Step 4: Refill the differential with the correct fluid type to the proper level.