Timing chain stretch and tensioner wear
Attaches to prince-timing-chain at component level · Engine · carried by 2 variants across 1 chassis
Overview
Timing chain stretch and tensioner wear is a common fault recorded against prince-timing-chain at component level, typically from 80–160k km. It shows up as a rattle from the front of the engine for the first seconds after a cold start, and later a rough idle or a fault code for camshaft timing. Where it's documented, the repair runs €1,100–€1,900 (chain, guides and tensioner at a specialist, with the engine in the car, costs dated 2026-07), and it can be checked before you buy. 2 variants across 1 chassis in this database inherit it.
What happens
Symptom. A rattle from the front of the engine for the first seconds after a cold start, and later a rough idle or a fault code for camshaft timing.
Cause. The chain and its tensioner on the BMW and PSA Prince family stretch with age and heat cycles rather than with distance. Once the chain is slack it can skip a tooth, and that damages valves.
How to check it
Cold start
Start the car from stone cold and listen carefully through the first five seconds. Any rattle means the work is due, so ask for a receipt rather than accepting an assurance.
You get one. If the engine is warm when you arrive, come back another day.
Every variant that carries this
| Variant | Chassis | Body | Years | Risk | Good buy | Cost as % of good buy |
|---|---|---|---|---|---|---|
| Cooper N12 | R56 | hatchback | 2006–2010 | R4 | €4,200 | 36% |
| Cooper S N14 | R56 | hatchback | 2006–2010 | R4 | €5,500 | 27% |
The last column is the point. The same repair is an inconvenience on one variant and a reason to scrap the car on another. A failure costing a quarter of the vehicle's value changes the purchase decision regardless of how rare it is.