my Volkswagen Golf MK7 (2015-2019) won't start in cold weather, what should I do?

Solution

1. Preparation

• Gather tools: multimeter, OBD-II scanner, socket set, jumper cables, and torque wrench.
• Ensure the vehicle is parked on a level surface and the parking brake is engaged.
• Disconnect the battery negative terminal to ensure safety.

2. Battery Inspection and Replacement

• Inspect the battery:
  • Remove the battery terminals (negative first, then positive).
  • Clean any corrosion from the terminals using a wire brush.
• Test the battery:
  • Use a multimeter to measure voltage; replace if below 12.4 volts.
• Replace the battery (if necessary):
  • Remove the battery from the tray using a socket wrench.
  • Install the new battery by placing it in the tray and securing it with bolts.
  • Reconnect the terminals (positive first, then negative).

3. Check and Replace Fuel System Components

• Inspect the fuel pump:
  • Turn the ignition to the "ON" position (do not start) and listen for the fuel pump's prime sound.
• Replace the fuel filter:
  • Locate the fuel filter, relieve fuel pressure, and remove it using appropriate tools.
  • Install a new fuel filter ensuring correct orientation.

4. Starter Motor Inspection and Replacement

• Inspect starter connections:
  • Check wiring and connections to the starter for signs of wear or corrosion.
• Test the starter motor:
  • If it fails, remove the starter from the engine (usually requires removing bolts and disconnecting wiring).
  • Replace it with a new starter, ensuring proper alignment and torque specifications (typically around 15-20 Nm).

5. Engine Oil Change (If Necessary)

• Check oil viscosity:
  • If the oil is too thick for cold weather, drain the old oil using a socket set and replace with the correct viscosity oil for winter conditions.
  • Replace the oil filter and refill with new oil.