In Volkswagen Beetle models manufactured after 1998, there are two different sizes of engines. When changing the spark plugs in a 2.0 liter engine, disconnect the fuel injectors to replace the spark plugs. In a 1.8 liter engine, remove the vacuum reservoir to access the spark plugs.
Turn off the car and allow the engine to cool for 30 minutes. Pop the hood and locate the spark plug wires. If the Beetle model's engine is 1.8 liters, the spark plugs are located on the top of the engine. For 2.0 liter engines, the spark plug wires are under the engine cover.
Loosen the screws on the side of the engine that hold the engine cover. Remove the cover. Disconnect the fuel injectors on the 2.0 liter engine. For a 1.8 liter engine, unscrew the vacuum reservoir and place it to the side.
Turn the spark plug wire from side to side to unlock the wire. Pull the wire by the boot or cover on the end of the spark plug. Replace each spark plug completely before moving to the next one to keep the spark plug wires from crossing.
Unscrew the spark plug with the socket and wrench. Pull the spark plug out of the engine block.
Blow or brush out any debris in the spark plug wire or in the cylinder well. This extends the life of the spark plug.
Apply silicon lubricant to the spark plug threads and to the inside of the boot.
Insert the spark plug into the engine block and tighten it by hand. Test the tension of the spark plug. Most spark plugs for a VW Beetle require a tension between 15 and 22 foot pounds. Consult the package to determine the correct tension needed. Different spark plug manufactures require different tensions.
Reconnect the spark plug cable and turn it in either direction to lock it in place.
Repeat Steps 2 through 8 for the remaining spark plugs. Replace the vacuum reservoir or the fuel injectors. Place the cover on the engine and secure it in place.