The 3.5L EcoBoost is a six-cylinder turbocharged V6. The cylinders are numbered 1 through 6, with odd-numbered cylinders on Bank 1 (1, 3, 5) and even-numbered cylinders on Bank 2 (2, 4, 6).
In practice, Bank 1 is one side of the V and Bank 2 is the opposite side; the arrangement is the standard Ford convention for the 3.5L EcoBoost used in models like the F-150, Expedition, and related vehicles. This numbering is used in maintenance guides, diagnostic trouble codes, and service procedures.
Cylinder numbering by bank
To identify which cylinders belong to which bank, use the following two-bank layout reference.
- Bank 1: Cylinders 1, 3, 5
- Bank 2: Cylinders 2, 4, 6
Knowing the bank division is helpful for following service instructions that specify a bank-based order or for diagnosing misfires by cylinder.
Notes for service manual reference
When consulting Ford service manuals or diagnostic codes, rely on the standard cylinder numbers: P0301 for cylinder 1 misfire, P0302 for cylinder 2, and so on up to P0306 for cylinder 6. The EcoBoost's six-cylinder arrangement makes these mappings consistent across model years that use the 3.5L V6 turbo configuration.
Summary
The 3.5 EcoBoost uses six cylinders numbered 1–6, with Bank 1 containing cylinders 1, 3, 5 and Bank 2 containing cylinders 2, 4, 6. This layout is used across Ford’s 3.5L EcoBoost applications for maintenance, diagnostics, and servicing.