BMW Ignition Service Kit - 12138616153KT6

Spark plugs and ignition coils are a pretty common overlooked item. This occurs because the components are out of site, out of mind so to speak: that is until your engine starts to have misfire codes.

Spark plugs wear out over countless of thousands of ignition cycles. The wear results in misfires and poor ignition performance because the gap between the center electrode and ground electrode becomes too big. Once this occurs with a spark plug it will need to be replaced.

Ignition coils provide the energy required for the spark plug to ignite the fuel mixtures. Over countless of thousands of ignition cylces the ignition coils will wear out. We typically see ignition coil boots wear out causing poor insulation between the spark plug and coil.

Installation tips:

When installing spark plugs on the S55 engine BMW recommends cleaning the spark plug tubes with compressed air before removing the spark plugs first. When removing the spark plugs you must use special tool 12 1 220 (83300495560) with an extension joint. To install the new spark plugs use special tool 12 1 230 (83300496065) to thread the spark plugs into the cylinder head until hand tight. Use special tool 12 1 220 with extension joint and then torque spark plugs to 23 ± 3 Nm (~17 ft lbs) of torque. BMW specifically recommends not using any graphite or copper grease (anti-zieze) when installing new spark plugs.