BMW 12129061882 Spark Plug

A regular spark plug has a metal shell, ceramic insulator and metal electrode that passes through the insulator with a side electrode connected to the outside shell. The spark plug gap between these electrodes is critical. It does not produce a spark but allows for current arcing, resulting from ignition coil transmitting high voltage to the spark plugs, which in turn initiates combustion of air/fuel mixtures inside the combustion chamber. Heat range of a spark plug affects its heat dissipation ability; deeper insulator position makes it run hotter while shallow one cools it down. An incorrect heat range may cause carbon deposits, fouling or pre-ignition. Replacement intervals depend on mileage and driving conditions with BMWs Inspection II maintenance usually falling between 30,000-40,000 miles. Furthermore, if vehicles have aluminum cylinder heads then replacement of spark plugs every two to four years is recommended due to possible corrosion. Some BMWs employ high-performance platinum spark plugs offering such advantages like better fuel efficiency and more reliable cold starts as well as reduced misfire rates. During inspection process carbon deposit could mean adjustment problems; oil fouling might indicate engine issues; damaged plug might suggest detonation. Take caution to remove one at a time in order to maintain proper cylinder order when removing each spark plug.Most importantly check their gaps if necessary adjusting them using appropriate tools.Besides cleaning them on a machine or by using wire brush before installation is inevitable.New ones should be examined and gapped suitably prior mounting.The gap recommended varies according to different models of BMWs and types of spark plugs although gapping must be done when only permitted for without weakening or breaking any side electrode while making adjustments.