What is the BMW N47 engine?
The BMW N47 is a 2.0-litre four-cylinder turbodiesel engine produced from 2007 to 2014. It powered some of BMW's best-selling models:
- 1 Series — 118d, 120d (E87/F20)
- 3 Series — 318d, 320d (E90/F30)
- 5 Series — 520d (F10)
- X1 — sDrive18d, sDrive20d (E84)
- X3 — sDrive18d, xDrive20d (F25)
Power output ranged from 105 hp to 184 hp depending on the variant, with torque figures between 260–380 Nm. On paper, it's a perfectly adequate diesel engine for daily driving.
The problem: rear-mounted timing chain
Unlike most engines that place the timing chain at the front (where it's accessible), BMW mounted the N47's timing chain at the rear, between the engine and gearbox. This means:
- The chain is invisible — you can't inspect it without major disassembly
- Replacement requires engine removal — 15+ hours of labour
- The chain stretches prematurely — typically between 80,000 and 120,000 km
When the chain stretches beyond tolerance, the timing slips. If it snaps, the pistons hit the valves and the engine is destroyed.
Symptoms to watch for
If you're test-driving a car with an N47, listen carefully:
- Rattling noise on cold start — a metallic rattle from the rear of the engine that fades after 10–30 seconds
- Check engine light — codes related to camshaft timing deviation (2A87, 2A88)
- Rough idle — chain stretch causes timing drift
- Loss of power — advanced chain wear affects valve timing
Warning: by the time symptoms appear, the chain may already be dangerously stretched. A pre-purchase inspection with a BMW specialist is essential.
Repair cost
| Repair | Cost estimate |
|---|---|
| Timing chain replacement (preventive) | €2,000–€3,000 |
| Timing chain replacement (after failure, if engine survived) | €3,000–€4,000 |
| Engine replacement (after chain snaps) | €5,000–€8,000 |
The repair is expensive because the engine or gearbox must come out. Budget €2,000–€4,000 for a proper preventive replacement.
EngineScope verdict: 35/100 — AVOID
The N47 scores 35 out of 100 on EngineScope — firmly in AVOID territory. The timing chain design is a fundamental engineering flaw that affects the majority of units. Combined with expensive repair costs and the risk of catastrophic failure, this is an engine to walk away from unless:
- The timing chain has already been replaced (with documentation)
- The car is priced significantly below market to account for the risk
- You budget €2,500+ for preventive replacement immediately after purchase
View the full BMW N47 reliability report on EngineScope →
What to buy instead
If you want a reliable 2.0 diesel BMW, look at:
- BMW B47 (2014+) — the N47's successor with a front-mounted timing chain. Much more reliable.
- Toyota 1AD-FTV — bulletproof 2.0 diesel found in the Avensis and RAV4.
- Mercedes OM651 — solid 2.1 diesel with higher repair costs but better longevity.