why does my Volkswagen Golf MK7 (2015-2019) make a knocking noise when starting?

Solution

1. Preparation

• Tools Required: Socket set, torque wrench, multimeter, OBD-II scanner, engine oil (if needed).
• Disconnect the negative battery terminal to ensure safety.
• Allow the engine to cool before starting any work.

2. Inspect and Replace Battery

• Check the battery voltage with a multimeter; replace if below 12.4 volts.
• Clean battery terminals with a wire brush and reconnect securely.
• If the battery is faulty, replace it with a new one, ensuring proper fit and terminal orientation.

3. Examine Starter Motor

• Remove the starter motor from the vehicle:
  • Disconnect wiring harness and remove mounting bolts.
  • Carefully extract the starter motor.
• Inspect the starter motor for signs of wear or damage.
• If defective, replace the starter motor with a new unit, ensuring to torque the mounting bolts to factory specifications.

4. Engine Oil Check and Change

• Check the engine oil level using the dipstick; add oil if low.
• If the oil is dirty or hasn’t been changed according to the schedule, drain and replace it:
  • Drain old oil using a wrench to remove the oil pan bolt.
  • Replace the oil filter.
  • Refill with the appropriate grade of engine oil, ensuring it is at the correct level.

5. Inspect Engine Mounts

• Visually inspect engine mounts for cracks or deterioration.
• If any mounts are compromised, replace them following these steps:
  • Support the engine using a jack and a block of wood to avoid damage.
  • Remove the bolts securing the mount to the chassis and engine.
  • Replace with new mounts, torqueing to manufacturer specifications.