Timing chain and guide wear
Attaches to N46 at engine level · Engine · carried by 6 variants across 3 chassis
Overview
Timing chain and guide wear is a common fault recorded against N46 at engine level, typically from 120–200k km. It shows up as rattle on cold start that becomes a constant chatter, then timing correlation faults. Where it's documented, the repair runs €1,000–€1,800 (gearbox out at an independent, costs dated 2026-07), and it can be checked before you buy. 6 variants across 3 chassis in this database inherit it.
What happens
Symptom. Rattle on cold start that becomes a constant chatter, then timing correlation faults.
Cause. Plastic chain guides wear and the chain stretches. The chain sits at the rear of the engine, so access is poor.
How to check it
Cold start
Cold start only. Any sustained rattle from the bulkhead end of the engine is this until proven otherwise.
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 |
|---|---|---|---|---|---|---|
| 318i N46 | E90 | sedan | 2005–2011 | R3 | €3,100 | 45% |
| 318i N46 | E91 | wagon | 2005–2011 | R3 | €3,300 | 42% |
| 320i N46 | E90 | sedan | 2005–2007 | R3 | €3,400 | 41% |
| 320i N46 | E91 | wagon | 2005–2007 | R3 | €3,600 | 39% |
| 118i N46 | E87 | hatchback | 2004–2007 | R2 | €2,900 | 48% |
| 120i N46 | E87 | hatchback | 2004–2007 | R2 | €3,250 | 43% |
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.