why does my Volkswagen Golf MK7 (2015-2019) have a rough idle when cold

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the engine is cool before starting work.
• Disconnect the battery to prevent electrical shorts.

2. Replace Engine Coolant Temperature Sensor

• Locate the engine coolant temperature sensor on the engine block.
• Disconnect the electrical connector from the sensor.
• Remove the sensor using a socket or wrench.
• Install the new sensor, making sure to use new O-rings if provided.
• Reconnect the electrical connector.

3. Clean Throttle Body

• Remove the air intake duct connected to the throttle body.
• Use throttle body cleaner and a soft cloth to clean the throttle plate and bore.
• Ensure no cleaner residue is left before reassembling.
• Reattach the air intake duct securely.

4. Inspect and Replace Spark Plugs

• Remove the ignition coil cover if applicable.
• Disconnect the ignition coils and remove them using a socket set.
• Take out the old spark plugs using a spark plug socket.
• Inspect the spark plugs for wear; replace them if necessary with new ones that meet OEM specifications.
• Reinstall the ignition coils and cover.