my BMW X3 F25 (2011-2018) makes a knocking noise when starting what's happening

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, multimeter, stethoscope (for noise detection).
• Safety Warnings: Disconnect the battery before working on electrical systems.

2. Change Engine Oil and Filter

• Sub-steps:
  1. Raise the vehicle and secure it on jack stands.
  2. Place an oil catch pan under the oil pan.
  3. Remove the oil drain plug and let the oil drain completely.
  4. Replace the oil filter using an oil filter wrench.
  5. Reinstall the drain plug and torque to the manufacturer's specifications.
  6. Fill the engine with new oil, using the correct type and amount as per the owner's manual.

3. Replace Engine Mounts (if damaged)

• Sub-steps:
  1. Support the engine with a jack and a wooden block to avoid damage.
  2. Remove the bolts securing the engine mounts to the frame using a socket set.
  3. Remove the old mounts and install new ones in the reverse order.
  4. Torque the mount bolts to the specified values.

4. Check Accessory Components

• Sub-steps:
  1. Visually inspect the alternator, power steering pump, and other accessories for wear.
  2. If noise persists, remove the belt and check each component individually.
  3. Replace any failing components as necessary.