Executive Summary
Looking for a reconditioned BMW 118d engine for sale in the UK? The F20/F40 1 Series primarily uses the B47 diesel (116d, 118d, 120d) and B48 petrol (118i, 120i, M135i) engines, with reconditioned units ranging from £1,800 to £3,500 plus labour. The B47 2.0-litre diesel dominates the used market, offering excellent fuel economy and 150,000+ mile potential, while the B48 turbo petrol provides spirited performance with typical replacement costs of £2,200 to £3,200.
Critical compatibility factors include your chassis code (F20 2011 to 2019 or F40 2019 to present), engine variant (B47D20/B48B20), and emissions standard (Euro 5/6 affects ULEZ compliance). Always verify engine codes match your V5C logbook before purchasing.
We are a price comparison platform, not a direct engine seller. Final pricing, warranty terms, and availability vary by vetted UK supplier. Professional diagnosis is recommended before purchasing any replacement engine.
BMW 1 Series Engine Options: B47 vs B48
B47 Diesel Engine (116d, 118d, 120d)
The B47D20 2.0-litre turbo diesel replaced the problematic N47 in 2015, addressing timing chain failures that plagued earlier models.
Available in:
- 116d: 116 bhp (B47C20A)
- 118d: 150 bhp (B47D20A)
- 120d: 190 bhp (B47D20B)
Production years: 2015 to present (F20 LCI, F40)
Known issues:
- EGR cooler leaks (symptom: coolant loss, white smoke)
- Timing chain stretches beyond 120,000 miles
- DPF clogging on short-journey driving
Replacement cost: £2,000 to £3,200 (reconditioned). Browse used BMW B47 diesel engines from vetted UK suppliers for engine-specific quotes.
B48 Petrol Engine (118i, 120i, M135i)
The B48B20 2.0-litre turbo petrol offers balanced performance and reliability across the 1 Series range.
Available in:
- 118i: 136 bhp (B48A20A)
- 120i: 178 bhp (B48B20B)
- M135i/M140i: 302 to 340 bhp (B58B30, 3.0L variant)
Production years: 2015 to present (F20 LCI, F40)
Known issues:
- Coolant leaks from thermostat housing
- Carbon buildup on intake valves (direct injection)
- Turbocharger wastegate rattle
Replacement cost: £2,200 to £3,500 (reconditioned). A full BMW engine replacement cost comparison can help you assess parts, labour, warranty and supplier differences before buying.
Engine Compatibility by Model
F20 Generation (2011 to 2019)
Pre-LCI (2011 to 2015):
- N47 diesel (avoid, timing chain issues)
- N13/B38 petrol (1.5L turbo)
LCI (2015 to 2019):
- B47 diesel (recommended)
- B48 petrol (recommended)
F40 Generation (2019 to present)
- B47 diesel (all variants)
- B48 petrol (118i, 120i)
- B38 1.5L 3-cylinder (118i entry model)
Critical checks:
- Verify engine code on V5C (section V.5)
- Confirm Euro 6 compliance for ULEZ cities using the GOV.UK clean air zones checker
- Check transmission compatibility (manual vs automatic)
Before ordering, verify fitment against your exact chassis, engine code and emissions specification.
Pricing Guide: Used vs Reconditioned
| Engine Type | Used | Reconditioned | Labour |
| B47 Diesel | £800-£1,500 | £2,000-£3,200 | £800-£1,200 |
| B48 Petrol | £900-£1,600 | £2,200-£3,500 | £700-£1,000 |
| B38 1.5L | £600-£1,200 | £1,600-£2,600 | £600-£900 |
Used engines: 3-to-6-month warranty, unknown history. Reconditioned engines: 12-to-24-month warranty, rebuilt to specification. Choose the option that best matches your budget, mileage, warranty expectations and risk tolerance.
Practical Takeaways
Best value: B47 diesel reconditioned engine (£2,000 to £3,200) for high-mileage drivers. Best performance: B48 petrol with upgraded turbo for M135i models. Avoid: Pre-2015 N47 diesel engines due to timing chain failure risk.
Before buying:
- Confirm engine code matches V5C
- Verify Euro emissions standard
- Check supplier warranty terms carefully, ideally with a minimum 12-month warranty on a reconditioned unit
- Get written quotes including VAT and delivery
Compare quotes from vetted UK suppliers for no-obligation pricing.
Frequently Asked Questions
What is the most reliable BMW 1 Series engine?
The B47 2.0-litre diesel (2015 to present) is the most reliable 1 Series engine, addressing the N47’s timing chain failures. With proper maintenance, B47 units achieve 150,000 to 200,000 miles. The B48 petrol is also dependable but requires more attentive service. Avoid pre-2015 N47 diesel engines due to catastrophic timing chain failure risk.
How much does a BMW 116d engine replacement cost?
A reconditioned BMW 116d (B47) engine costs £1,800 to £2,800 including VAT, with labour adding £800 to £1,200. Used units are cheaper (£700 to £1,400) but carry higher risk. Total replacement typically ranges from £2,600 to £4,000 depending on supplier warranty terms and garage rates.
Can I fit a B48 engine in my F20 1 Series?
Yes, B48 engines are compatible with F20 1 Series from 2015 onwards (LCI models). Pre-2015 F20s used N13/N47 engines and require ECU reprogramming for B48/B47 swaps. Ensure emissions standard matches (Euro 5/6) to maintain ULEZ compliance. Professional coding (£150 to £300) is essential for immobiliser synchronization and optimal performance.
What’s the difference between B47 and N47 engines?
The B47 replaced the N47 in 2015 with reversed rotation design, improved timing chain location (front-mounted), and enhanced reliability. N47 engines suffered catastrophic timing chain failures (repair cost £1,500+), while B47 units resolved this issue. B47 also features improved fuel economy (60 to 70 mpg vs 50 to 60 mpg) and lower emissions. Always choose B47 over N47 for F20 replacements.
Ready to compare quotes? We connect you with vetted UK suppliers for no-obligation pricing.