machine · note · in motion
BMW X1 28i (2017) — coils + plugs reset
A baseline reset, not a chase. Full coil and plug set replaced in one pass so any subsequent diagnosis starts from a known-good ignition.
Why a full set, not just one
Diagnosing a misfire one coil at a time is fine when the symptom is sharp and isolated. When the symptom is fuzzy, or when the whole set is the same age, replacing one coil pushes the problem to the next-weakest one and the same diagnosis repeats. The honest move at this mileage is one pass, the whole set, then drive it.
What the pass is
- Full set of plugs to spec, gapped and torqued.
- Full set of coils.
- Cabin air filter and engine air filter checked while everything is open — five extra minutes when the cover is already off.
- Codes cleared, then a couple of drive cycles to see whether anything new comes back.
Next
Drive a couple of cycles. Scan. If the readiness monitors come up clean and idle behaviour is good, this note closes. If anything returns, the next note is the diagnosis that starts from this baseline.