BMW N55 Engine Firing Order Diagram

Reading the N55B30 3.0L Inline-Six diagram correctly

Cylinders are numbered 1-2-3-4-5-6 in a single row from the front accessory/radiator end toward the flywheel and transmission. Read the vehicle as installed and use the manufacturer's left/right convention, not the side from which you happen to be standing. The first cylinder listed in 1-5-3-6-2-4 begins the sequence but does not define a universal connector position.

BMW's Engine Technology training manual explicitly groups the N55 with its inline-six cylinder arrangement and lists firing order 1-5-3-6-2-4. The N55 training material also groups cylinders 1-3 and 4-6 into the twin-scroll exhaust channels, which is an exhaust-pulse arrangement rather than two cylinder banks. BMW diagnostic screens may arrange smooth-running values or test steps differently from physical front-to-rear cylinder order. A fault for cylinder 5 refers to the fifth physical cylinder from the front, not the second event in the firing sequence. On coil-on-plug engines, use the diagram for cylinder identity and diagnosis; the PCM, not a physical distributor cap, schedules spark.

Which N55B30 3.0L Inline-Six firing order applies?

BMW's Engine Technology training manual explicitly groups the N55 with its inline-six cylinder arrangement and lists firing order 1-5-3-6-2-4. The N55 training material also groups cylinders 1-3 and 4-6 into the twin-scroll exhaust channels, which is an exhaust-pulse arrangement rather than two cylinder banks. This distinction matters because the engine can look nearly identical from above. Treat the camshaft or engine assembly as the authority when parts have been mixed. A firing order cast into an intake, copied from a generic decal, or remembered from another V8 is not enough to identify a modified engine.

The application table separates the order, cylinder banks, and ignition-system notes. Read all columns before routing. The first number in 1-5-3-6-2-4 is cylinder 1, but the physical No. 1 terminal can appear in different clock positions when a distributor has been installed on a different gear tooth.

Bank numbering and verification on the N55B30 3.0L Inline-Six

BMW diagnostic screens may arrange smooth-running values or test steps differently from physical front-to-rear cylinder order. A fault for cylinder 5 refers to the fifth physical cylinder from the front, not the second event in the firing sequence.

BMW's Engine Technology training manual explicitly groups the N55 with its inline-six cylinder arrangement and lists firing order 1-5-3-6-2-4. The N55 training material also groups cylinders 1-3 and 4-6 into the twin-scroll exhaust channels, which is an exhaust-pulse arrangement rather than two cylinder banks.

Procedures used with this specification

These steps are the same for every vehicle in this family, so they are documented once rather than repeated on each page. The values above remain specific to this BMW N55B30 3.0L Inline-Six.