Section 1 - Prepare the Engine for Removing the Spark Plugs and Ignition Coils Preparing the engine so the N20 spark plugs and ignition coils can be accessed is a relatively easy procedure taking less than 15 minutes. Please note that it is important that the strut braces are loosened (step 9) to create enough space to get the upper partition out without breaking it.

Lift the strut braces and maneuver the top partition underneath them. Remove the partition from the vehicle. Remove the engine cover. If it is held in place with screws, unscrew them. If there are no screws visible, pull the cover off. Spark plug holes are deep and usually under an angle. Access to some parts of the engine can be limited. This means you can easily cross-thread the new spark plugs while installing them. To prevent this, use a rubber hose as a flexible tool that will allow you to install the spark plug safely. This way, the rubber hose will slip if the plug starts to cross-thread. Visually inspect the spark plug. It can tell you a lot about the state of the engine and that cylinder in particular. Visually inspect the spark plug hole for debris or oil. If there is any, clean it before taking the spark plug out. Take extra caution, as any debris left might fall into the cylinder when the spark plug is removed.

Recommended BMW Spark Plug Replacement Interval

Applications: most Citroën vehicles plus other manufacturers fitted with Bosch spark plugs, including: BMW E90 335I N54 engine (2006), Mercedes-Benz (M156 engine), MINI, Peugeot 207 and 307, Renault 1.2L 16v." Insert a new ignition coil into the spark plug tube and install the electrical plug. Make sure the plug is pushed in snugly as far as it will go into the ignition coil. DO NOT apply dielectric grease to the ignition coil...this will cause the coil to slip off of the spark plug causing a misfire. Yet, it is possible to have problems with spark plugs before you reach this interval. This can be caused by poor-quality fuel, high oil consumption, or fuel injection system-related problems. Also, ignition coils can fail as a result of damage or deterioration. What size are BMW Spark Plugs? Remove the drain tray installed below the windshield to access the spark plugs at the rear part of the engine. On some models, a strut brace is installed over the engine. It can be removed to gain better access, but it is unnecessary.

Push the upper side of the spark plug into the 3/8″ rubber hose. Using a 3/8″ rubber hose as a hand tool, screw the sparks plug hand-tight into the cylinder head plug thread as far as it will go. Older engines have ignition coils with detachable connector rubber boots. If your engine has these, they will likely detach from the ignition coil when you pull. You will need to pull them out separately. Traces of engine oil on the ignition coil boot indicate a leaking valve cover (cam cover) gasket. As oil is very aggressive on silicon boot insulation, so cam cover seal must be renewed before reinstalling ignition coils.What you may notice if your BMW spark plugs are worn out or not replaced at the recommended interval. Les applications comprennent : véhicules BMW : Série 1 (E81, E87-N43B), Série 3 (E90-N43B) et Série 5 (E60-N43B). Renew the boots on engines with ignition coils with detachable connector rubber boots. Apply a small amount of silicone grease on the inner spark plug side of the boot before reinstalling.