how to fix P0021 camshaft position timing over-advanced in Volkswagen Golf MK5 (2004-2008)?

Learn how to diagnose and fix P0021 camshaft position timing issue in Volkswagen Golf MK5. Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface, and the ignition is turned off.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Change Engine Oil

• Sub-steps:
  1. Drain the old engine oil using a drain pan.
  2. Replace the oil filter with a new one.
  3. Refill the engine with fresh oil that meets VW specifications (usually 5W-30 synthetic oil).
• Tools Required: Oil drain pan, socket set, oil filter wrench.

3. Inspect and Replace VVT Solenoid

• Sub-steps:
  1. Remove the engine cover (if applicable) for access.
  2. Disconnect the electrical connector from the VVT solenoid.
  3. Unbolt and remove the VVT solenoid from its housing.
  4. Install the new VVT solenoid and torque the bolts to the manufacturer's specifications (typically around 10 Nm).
  5. Reconnect the electrical connector.
• Tools Required: Socket set, torque wrench.

4. Adjust Camshaft Timing

• Sub-steps:
  1. Remove the timing cover to access the camshaft and timing chain/belt.
  2. Align the engine to Top Dead Center (TDC) on the compression stroke of the first cylinder.
  3. Check the timing marks on the camshaft and crankshaft gears; they should align according to the service manual.
  4. If misaligned, loosen the camshaft sprocket bolts and adjust the timing as necessary, then retighten to manufacturer's torque specifications (usually around 20 Nm).
• Tools Required: Timing tool set, socket set, torque wrench.

5. Reassemble and Test

• Sub-steps:
  1. Reinstall the timing cover and engine cover.
  2. Reconnect the negative battery terminal.
  3. Start the engine and allow it to reach operating temperature.
• Safety Warnings: Ensure timing marks are correctly aligned to prevent engine damage.