why does my BMW 5 Series make a knocking noise when starting

Solution

1. Preparation

• Tools Required:
  • OBD-II scanner
  • Socket set
  • Torque wrench
  • Compression tester
• Ensure the vehicle is parked on a level surface and the engine is cool before starting.

2. Change Engine Oil

• Sub-steps:
  1. Lift the vehicle using a jack and secure it with jack stands.
  2. Remove the oil drain plug with a socket set and drain the old oil into a pan.
  3. Replace the oil filter using an oil filter wrench.
  4. Install a new oil filter and ensure it is tightened according to specifications.
  5. Reinstall the drain plug and torque it to the manufacturer's specifications.
  6. Fill the engine with the recommended oil type using a funnel.

3. Replace Timing Chain/Belt (if necessary)

• Sub-steps:
  1. Disconnect the negative battery terminal.
  2. Remove any components obstructing access to the timing chain or belt (e.g., front covers).
  3. Align timing marks as per the service manual.
  4. Remove the old timing chain/belt and inspect timing gears for wear.
  5. Install the new timing chain/belt, ensuring proper alignment of timing marks.
  6. Reassemble removed components and reconnect the battery.