Valvetronic motor performance — BMW N12/N14/N16 (Mini Cooper too) Valvetronic eccentric shaft sensor or motor failure.
BMW P1004 — Valvetronic motor performance — BMW N12/N14/N16 (Mini Cooper too) Valvetronic eccentric shaft sensor or motor failure. Typical UK independent garage cost: £180–£1600.
What actually causes P1004 on a BMW
On the Mini-shared 1.6 N14 engine the Valvetronic eccentric shaft sensor fails — engine goes into limp mode and won't rev past 3,000 RPM. The sensor itself is £80 but if the eccentric shaft has worn (caused by oil starvation from a failed VANOS or timing chain), the whole motor assembly needs replacing.
BMW engines that log P1004
- N12/N14/N16 1.6 (Mini Cooper R56/R55, BMW 116i E87)
- N18 1.6 turbo (Mini Cooper S R56/F56)
- N52/N53 inline-6 with Valvetronic
How we diagnose P1004 on a BMW
- Read live Valvetronic position vs commanded in INPA / ISTA
- Inspect eccentric shaft wear with valve cover off
- Check oil condition — sludged oil starves the Valvetronic motor
- Test sensor resistance and signal
The common misdiagnosis to avoid
A new eccentric shaft sensor without checking shaft wear is a temporary fix — if the shaft is worn, the new sensor will throw the same code in months.
BMW P1004 repair cost in the UK
Expect £180–£1600 including parts and labour at an independent garage. Main-dealer quotes on BMW are usually higher for the same job, and the spread exists because the cheap cause and the expensive cause throw the same code — pay for the diagnosis before you pay for parts.
Bob's workshop tip
If you've got a Mini Cooper R56 with this code, also pull the spark plugs — these engines suffer chronic carbon build-up which causes simultaneous misfires that get blamed on Valvetronic. Walnut blast at the same time saves a second strip-down later.
Codes usually seen alongside P1004 on BMW
- P10DF
- P052E
- P0014