why does my Volkswagen Golf MK7 (2015-2019) have a hard time starting in the cold?

Solution

1. Preparation

• Gather Tools: OBD-II scanner, multimeter, fuel pressure gauge, socket set, torque wrench.
• Safety Precautions: Disconnect the battery before starting any electrical work and ensure the engine is cool.

2. Battery Inspection and Replacement

• Check Battery Condition:
  1. Use a multimeter to measure the battery voltage; it should read above 12.4 volts.
  2. If the voltage is low, perform a load test to confirm the battery's condition.
• Replace Battery (if necessary):
  1. Disconnect the negative terminal first, followed by the positive terminal.
  2. Remove the battery hold-down bracket and lift the battery out.
  3. Install the new battery, ensuring the positive terminal is connected first, then the negative.

3. Starter Motor Inspection and Replacement

• Inspect Starter:
  1. Check the starter motor for loose connections and physical damage.
  2. Test the starter with a multimeter to check for proper voltage during cranking.
• Replace Starter (if necessary):
  1. Remove electrical connections from the starter motor.
  2. Unbolt the starter from the engine and remove it.
  3. Install the new starter and reconnect all wiring, ensuring they are secure.

4. Fuel System Check and Repair

• Check Fuel Pressure:
  1. Connect a fuel pressure gauge to the fuel rail.
  2. Turn the ignition on without starting the engine and check the pressure; it should meet specifications.
• Replace Fuel Pump (if necessary):
  1. If fuel pressure is low, access the fuel pump by removing the rear seat or trunk panel.
  2. Disconnect wiring and fuel lines from the pump assembly.
  3. Remove the fuel pump and install the new unit, ensuring all connections are tight.

5. Coolant Temperature Sensor Replacement

• Replace Coolant Temperature Sensor:
  1. Locate the sensor on the engine block and disconnect the electrical connector.
  2. Remove the sensor using a socket and install the new one.
  3. Reconnect the electrical connector and ensure there are no leaks.