BMW P0016

Crank/cam correlation on BMW N47 / N57 diesels — the timing chain is at the rear of the engine and notorious for stretching and snapping.

BMW P0016 — Crank/cam correlation on BMW N47 / N57 diesels — the timing chain is at the rear of the engine and notorious for stretching and snapping. Typical UK independent garage cost: £1400–£3500.

What actually causes P0016 on a BMW

BMW's N47 diesel mounted the timing chain at the rear (gearbox end) of the engine to save space — but the chain tensioner and guides wear quickly, the chain stretches, and eventually it can snap. P0016 (and often P0017/P0008) is the warning shot before catastrophic failure. The job requires the engine and gearbox to be separated — a 12–18 hour labour bill. N57 is similar but more durable. N20 petrol has its own chain-at-the-front issues that also throw P0016.

BMW engines that log P0016

• N47 2.0d (1, 3, 5 Series, X1, X3 2007–2014)
• N57 3.0d (3, 5, 7 Series, X5, X6)
• N20 2.0 petrol (later models)

How we diagnose P0016 on a BMW

1. Listen for diesel chain rattle from the rear of the engine, especially on cold start and overrun
2. Scan tool (ISTA or equivalent): read cam timing deviation — anything over 6° crank degrees is serious
3. Check service history for previous chain work and what parts/spec was used
4. If chain confirmed stretched, plan engine-out job with full BMW chain kit (genuine, not pattern)
5. Replace rear main seal and inspect oil pump chain while engine is out

The common misdiagnosis to avoid

Don't let a non-BMW specialist quote 'chain only' — the guides, tensioner, sprockets and seals all need doing together, and the rear main seal usually needs replacing while you're in there. A botched N47 chain job is money down the drain.

BMW P0016 repair cost in the UK

Expect £1400–£3500 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

N47s under 80k with a full BMW service history and short oil-change intervals (8k miles, not 18k) are far less likely to fail — when buying used, walk away from anything on long-life servicing without proof of chain replacement.

Codes usually seen alongside P0016 on BMW

• P0017
• P0008
• P0335

Symptoms drivers report with P0016

• Loud metallic rattle for the first 2–4 seconds of a cold start — the classic 'death rattle'
• Long cranking before the engine catches, especially after standing overnight
• Rough lumpy idle at traffic lights, occasionally stalls
• Stop/Start stops working (ECU disables it once cam correlation drifts)
• Turbo feels lazy or flat below 2,000 RPM — timing is retarded to protect the valvetrain
• MPG drops 4–8 mpg with no other obvious cause
• Code P0011, P0014, P0017 or P0341 stored alongside P0016

Repairs that clear P0016

• Measure cam-to-crank deviation with manufacturer-aware scan tool
• Plan full timing chain kit if stretched
• Replace cam phaser if mechanically faulty

For the generic, all-makes explanation of this code — meaning, every known cause and UK cost bands — see our P0016 guide.

Reading P0016 on a BMW properly

A generic reader will show P0016 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 BMW 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 P0016 without fixing it

Erasing the code resets the BMW'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 P0016 is showing on your BMW, 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.