Mini P0507

Idle speed higher than expected on Mini — N12/N14/N18 Prince engine vacuum leak from PCV.

Mini P0507 — Idle speed higher than expected on Mini — N12/N14/N18 Prince engine vacuum leak from PCV. Typical UK independent garage cost: £180–£580.

What actually causes P0507 on a Mini

Mini Prince engine P0507 — PCV diaphragm in the rocker cover. Whole rocker cover replacement is the proper fix.

Mini engines that log P0507

• N12/N14 1.6 (R56)
• N18 1.6 (R56/R60)
• B38 1.5 (F56)

How we diagnose P0507 on a Mini

1. Smoke-test intake
2. Oil filler suction test
3. Whole rocker cover replacement

The common misdiagnosis to avoid

Mini dealer pricing is brutal — independent BMW specialist saves 40%.

Mini P0507 repair cost in the UK

Expect £180–£580 including parts and labour at an independent garage. Main-dealer quotes on Mini 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

Mini Cooper P0507 — rocker cover with PCV. £280 part trade.

Codes usually seen alongside P0507 on Mini

• P0171
• P1004

Symptoms drivers report with P0507

• The car feels like it's 'creeping' forward too fast at traffic lights without touching the gas.
• Engine revs stay hung up at 1200rpm when you dip the clutch approaching an intersection.
• A noticeable 'hissing' or whistling noise from the engine bay when idling on the driveway.
• The stop-start system has stopped working because the idle isn't stable enough for the ECU.
• Surging or 'hunting' revs when you first start it from cold in the morning.

Repairs that clear P0507

• Smoke-test intake
• Clean throttle body
• Replace PCV valve / rocker cover
• Inspect all vacuum hoses

For the generic, all-makes explanation of this code — meaning, every known cause and UK cost bands — see our P0507 guide.

Reading P0507 on a Mini properly

A generic reader will show P0507 and nothing else. What matters is the freeze-frame data stored with it — engine speed, load, coolant temperature and fuel trims at the moment the fault was logged — plus whether any other module on the Mini has logged something at the same time. Codes rarely arrive alone, and the order they were stored in usually points at which one is the cause and which are the consequences.

Clearing P0507 without fixing it

Erasing the code resets the Mini's readiness monitors as well as the light. The fault returns on the next drive cycle if the cause is still there, and in the meantime the incomplete monitors can stop the car passing an emissions check. After a genuine repair, the car is driven until the relevant monitor completes before it is handed back.

Bob's Mechanical Repairs is an independent garage in Birnam, Dunkeld, Perthshire, with 32 years of Bob's experience on the tools. If P0507 is showing on your Mini, bring any scan results with you — we will read the live data ourselves, confirm which cause it actually is, and price the repair before any work starts.