BMW 3 Series Buyers Guide: E90 vs F30 — Which to Buy?
The BMW 3 Series is the benchmark sports saloon. It's also one of the most common used cars in the UK — and one of the most discussed when it comes to reliability.
BMW 3 Series E90 (2005-2013)
Reliability factor: 0.78 Insurance group: 28 MPG: 36 Annual service cost: £450
Common faults:
- Electric water pump — Electric water pump failure (no warning) (£350-£600, avg 75k miles)
- Brake lines — Brake pipe corroded or leaking (£80-£200, avg 135k miles)
- Oil filter housing gasket — Oil filter housing gasket leak (£150-£300, avg 60k miles)
- VANOS solenoids — VANOS failure causing rough idle (£200-£400, avg 70k miles)
- Shock absorbers — Shock absorber leaking or ineffective (£150-£350, avg 124k miles)
The N47 Diesel Warning
The N47 diesel engine (320d E90) is the elephant in the room. The timing chain runs at the back of the engine, and when the chain stretches (from 50,000 miles), the repair involves removing the gearbox. Budget £2,000-£3,000. This is the single biggest risk with any E90.
The N52 petrol (325i, 330i) is much more reliable — a naturally aspirated straight-six that's one of BMW's best engines.
BMW 3 Series F30 (2011-2019)
Reliability factor: 0.82 Insurance group: 30 MPG: 42 Annual service cost: £480
Common faults:
- Electric water pump — Electric water pump failure (£400-£700, avg 70k miles)
- Oil filter housing gasket — Oil filter housing gasket leak (£150-£350, avg 50k miles)
- EGR valve — EGR valve failure on diesel (£300-£550, avg 75k miles)
- Timing chain — Timing chain stretch on B47/B48 (£1.2k-£2.5k, avg 80k miles)
- Brake pads — Brake pads worn below minimum (£80-£160, avg 78k miles)
Engine Choice
The F30 moved to turbocharged engines across the range:
- 320i (B48) — reliable four-cylinder turbo. The safe choice.
- 320d (B47) — improved over the N47. Timing chain is at the front and more accessible. Still a diesel with DPF considerations.
- 330i (B48) — same engine as 320i but higher tune. Reliable.
- 335i (N55) — turbocharged straight-six. Powerful but expensive when things go wrong.
E90 vs F30: Which to Buy?
| E90 | F30 | |
|---|---|---|
| Reliability | 0.78 | 0.82 |
| Service cost | £450/yr | £480/yr |
| Price range | £2,000-£8,000 | £6,000-£18,000 |
| Best engine | N52 325i petrol | B48 320i petrol |
| Biggest risk | N47 timing chain | DPF on diesels |
On a budget? E90 325i petrol manual. Avoid the N47 diesel at all costs.
Want newer? F30 320i petrol. Reliable engine, modern features, still great to drive.
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