BMW 1 Series F20Hatchback2011–2019
Engine Database
Every engine fitted to the F20/F21 1 Series — spanning three engine generations (N13, N20, N47, N55, B38, B37, B47, B48, B58) across petrol, diesel and six-cylinder variants.
Overview
The F20 is the second generation of the BMW 1 Series, launched in September 2011 as the successor to the E87. It introduced a longer wheelbase (+30mm), wider track (+51mm front, +72mm rear), and improved interior space while retaining rear-wheel drive — a layout that set it apart from front-driven hatchback competitors. The engine line-up was all-turbocharged from launch, initially featuring 1.6-litre four-cylinder petrols (N13) and 2.0-litre four-cylinder diesels (N47).
A significant February 2015 facelift (LCI) brought new engine families — the B38 three-cylinder, B48 four-cylinder and B58 six-cylinder — replacing the older N13, N20 and N47 units. The range-topper evolved from the N55-powered M135i to the B58-powered M140i in 2016.
Key Facts
Market Intelligence
The F20 1 Series generated 344 real UK engine enquiries in 2025 [BMW-VERIFIED], concentrated on the diesel variants (116d, 118d, 120d) as the range reaches affordable used-car territory.
04Best & Worst Engines
Best Petrol Overall
B58B30 (M140i, 340 bhp)
“BMW's B58 straight-six is a masterpiece — smooth, responsive, and robust. The M140i is the last of the rear-drive 1 Series hot hatches, and this engine is the highlight. Fewer known issues than the N55 it replaced, and a stronger bottom end.”
Who it's for: enthusiasts who want the ultimate F20 experience.
Best Diesel Overall
B47D20A (post-LCI 116d/118d/120d, 116–190 bhp)
“The B47 is a significant improvement over the N47 — timing chain issues are far less frequent, and the engine is smoother and more refined. The 120d (190 bhp) offers the best blend of performance and economy.”
Who it's for: buyers who want diesel economy without the N47's timing chain anxiety.
Highest Risk
N47D20C/D (pre-LCI 116d/118d/120d/125d)
“The N47 diesel family carries the infamous rear-mounted timing chain risk — cold-start rattle is the warning, and a snapped chain means full replacement. The 125d's twin-turbo setup adds further complexity.”
Who it's for: buyers on a budget who are willing to accept the chain risk.
Most Expensive Failure
N55B30 (M135i, 320–326 bhp)
“The N55 is a great engine, but it's the most expensive to replace in the F20 range — HPFP, VANOS and turbo issues can add up quickly. The B58 that replaced it is more robust.”
Who it's for: M135i buyers with deep pockets and full service history.
Best Value
B48B20 (post-LCI 120i/125i, 184–224 bhp)
“The 2.0-litre B48 petrol is the sweet spot — more reliable than the N13 it replaced, with strong performance and reasonable running costs. The 125i (224 bhp) offers near-M135i performance without the six-cylinder running costs.”
Who it's for: buyers who want petrol performance without the M135i's premium.
Most Overlooked
B38B15 (post-LCI 116i/118i, 109–136 bhp)
“The 1.5-litre three-cylinder B38 is often dismissed as 'the entry-level engine' — but it's a gem. Smooth, characterful, and significantly more reliable than the N13 it replaced. The 118i (136 bhp) is surprisingly punchy and returns excellent fuel economy.”
Who it's for: buyers who prioritise running costs and don't need six-cylinder power.
Best Petrol Overall
B58B30
(M140i, 340 bhp)
“BMW's B58 straight-six is a masterpiece — smooth, responsive, and robust. The M140i is the last of the rear-drive 1 Series hot hatches, and this engine is the highlight. Fewer known issues than the N55 it replaced, and a stronger bottom end.”
Who it's for: enthusiasts who want the ultimate F20 experience.
Best Diesel Overall
B47D20A
(post-LCI 116d/118d/120d, 116–190 bhp)
“The B47 is a significant improvement over the N47 — timing chain issues are far less frequent, and the engine is smoother and more refined. The 120d (190 bhp) offers the best blend of performance and economy.”
Who it's for: buyers who want diesel economy without the N47's timing chain anxiety.
Highest Risk
N47D20C/D
(pre-LCI 116d/118d/120d/125d)
“The N47 diesel family carries the infamous rear-mounted timing chain risk — cold-start rattle is the warning, and a snapped chain means full replacement. The 125d's twin-turbo setup adds further complexity.”
Who it's for: buyers on a budget who are willing to accept the chain risk.
Most Expensive Failure
N55B30
(M135i, 320–326 bhp)
“The N55 is a great engine, but it's the most expensive to replace in the F20 range — HPFP, VANOS and turbo issues can add up quickly. The B58 that replaced it is more robust.”
Who it's for: M135i buyers with deep pockets and full service history.
Best Value
B48B20
(post-LCI 120i/125i, 184–224 bhp)
“The 2.0-litre B48 petrol is the sweet spot — more reliable than the N13 it replaced, with strong performance and reasonable running costs. The 125i (224 bhp) offers near-M135i performance without the six-cylinder running costs.”
Who it's for: buyers who want petrol performance without the M135i's premium.
Most Overlooked
B38B15 (post-LCI 116i/118i, 109–136 bhp)
“The 1.5-litre three-cylinder B38 is often dismissed as 'the entry-level engine' — but it's a gem. Smooth, characterful, and significantly more reliable than the N13 it replaced. The 118i (136 bhp) is surprisingly punchy and returns excellent fuel economy.”
Who it's for: buyers who prioritise running costs and don't need six-cylinder power.
Engine
Typical Mileage
Common Major Failure
Repair Cost (Specialist)
Replacement Cost (Recon)
Ownership Verdict
Risk vs Reward -chain issues common on early cars.
Solid Choice -more robust than N13.
Safe Bet -the most reliable petrols in the range.
High Risk -rear chain is this engine's defining weakness.Solid Choice -significantly improved over N47.Premium Cost -fast, but costly to maintain.Best Petrol -the most robust six-cylinder in the range.EngineTypical MileageCommon Major FailureRepair Cost (Specialist)Replacement Cost (Recon)Ownership VerdictRisk vs Reward -chain issues common on early cars.Solid Choice -more robust than N13.Safe Bet -the most reliable petrols in the range.High Risk -rear chain is this engine's defining weakness.Solid Choice -significantly improved over N47.Premium Cost -fast, but costly to maintain.Best Petrol -the most robust six-cylinder in the range.
The F20 rule
A £3,200–£6,000 N47 recon against a £3,000–£12,000 F20 sits at 27–200% of the car's value【EM-VERIFIED】. On a sub-£4,000 example, that brushes our 70% BMW scrap threshold -we'll honestly tell you to walk away. Against a well-kept £8,000+ example, the same recon drops to 40–75% -a repair decision, not a financial one. Value the car first. For B58 M140i cars, the high retained value (£10,000–£18,000+) means replacement is almost always viable.
Key Takeaways
Which F20 Costs Least To Own?
B38 116i/118i -simple three-cylinder, fewer failure modes, cheap parts.
Which F20 Costs Most To Own?
N55 M135i -HPFP and VANOS repairs add up fast.
Which F20 Is Best Value?
B47 120d (post-LCI) -strong performance, excellent economy, and none of the N47's timing chain anxiety.
N47
Diesel Timing Chain Stretch (Pre-LCI)
Affected models:
F20 116d, 118d, 120d, 125d (2011–2015, N47 engine).
Typical failure mileage:
60,000–120,000 miles.
Root cause:
The rear-mounted timing chain receives the last oil feed and is tensioned by a plastic guide that degrades over time -cold-start rattle for 1–2 seconds is the classic early warning. The 125d's twin-turbo setup adds additional strain.
Tiered Cost Table
Preventative (Repair)
Dealer
Specialist
£1,800–£2,500
£650–£1,800
Replace chain, tensioner and guides
Catastrophic (Replacement)
Dealer
Specialist
£6,000–£8,500
£3,200–£6,000
Full reconditioned engine replacement
Our Recommendation
At the first sign of cold-start rattle on any N47 diesel F20, get the chain inspected immediately -a £650–£1,800 preventative repair is dramatically cheaper than the £3,200–£6,000 replacement that follows if ignored. On an F20 worth under £4,000, this decision alone determines whether the car stays economically viable.
N13
Petrol Timing Chain & VANOS Issues (Pre-LCI)
Affected models:
F20 114i, 116i, 118i, 120i (2011–2015, N13 engine).
Typical failure mileage:
50,000–100,000 miles.
Root cause:
The N13 (Prince engine, co-developed with PSA) can suffer from timing chain tensioner wear and VANOS solenoid failure. The chain is located at the front of the engine, making replacement less labour-intensive than the N47, but failure is still catastrophic if ignored.
Tiered Cost Table
Preventative (Repair)
Dealer
Specialist
£1,200–£2,000
£600–£1,500
Chain, tensioner and VANOS solenoid replacement
Catastrophic (Replacement)
Dealer
Specialist
£5,000–£7,000
£2,500–£4,500
Full reconditioned engine replacement
Our Recommendation
Have the timing chain and VANOS system inspected at 60,000 miles -a £600–£1,500 preventative service is far cheaper than the £2,500–£4,500 replacement that follows a catastrophic failure. Early N13s are the highest risk.
B38
/ B48 / B58 Cooling System Leaks (Post-LCI)
Affected models:
F20 116i, 118i, 120i, 125i, M140i (2015–2019, B38/B48/B58 engines).
Typical failure mileage:
40,000–80,000 miles.
Root cause:
The B-family engines (B38, B48, B58) are generally reliable, but they can suffer from coolant leaks from the water pump and plastic cooling system components -a known weakness on BMW's modular engine family.
Tiered Cost Table
Preventative (Repair)
Dealer
Specialist
£600–£1,200
£400–£800
Water pump and hose replacement
Catastrophic (Replacement)
Dealer
Specialist
£5,000–£8,000
£3,800–£7,000
Full engine replacement if overheating caused damage
Our Recommendation
Have the cooling system inspected annually and replace the water pump as preventative maintenance at 60,000 miles -a £400–£800 specialist job is trivial against the £3,800+ engine replacement that follows an ignored coolant leak.
B47
Diesel EGR Cooler Failure (Post-LCI)
Affected models:
F20 116d, 118d, 120d (2015–2019, B47 engine).
Typical failure mileage:
60,000–120,000 miles.
Root cause:
The B47's EGR cooler can develop internal leaks, allowing coolant to enter the exhaust system. This can lead to reduced performance and, in extreme cases, engine damage. BMW issued recalls for this issue on some models.
Tiered Cost Table
Preventative (Repair)
Dealer
Specialist
£800–£1,500 (recall may cover)
£500–£1,000
EGR cooler replacement
Catastrophic (Replacement)
Dealer
Specialist
£5,000–£8,000
£4,000–£6,500
Full engine replacement if coolant contamination caused damage
Our Recommendation
Check your B47 F20's VIN against any outstanding EGR cooler recalls -if affected, the repair is free. If not, have the EGR cooler inspected at 60,000 miles -a £500–£1,000 replacement is cheap insurance against a £4,000+ engine failure.
VariantEngine Code
Used (Supply)
Reconditioned (Supply)
Rebuilt (Supply)
Labour HoursNo Generation variance from the EM_Proprietary_Data baseline figures -F20 1 Series shares the L7 platform with other BMW models, with similar engine-bay access, so costs are inherited directly per the Authority Model, with no divergence note required.
Scope note: All variants listed are F20 (5-door) and F21 (3-door) 1 Series. The 116d EfficientDynamics Edition (2012–2015) used a 1.6-litre N47 diesel rather than the 2.0-litre. M135i (2012–2016) used the N55 six-cylinder; M140i (2016–2019) used the B58 six-cylinder. Post-LCI (2015–2019) models switched from N13/N20/N47 to B38/B48/B47/B58 engines.
Most Requested Engines (2025)
Most Requested Variants
Average Replacement Cost
£4,200
reconditioned, supply only
[BMW-QUOTE]
Most Common Failures
Live FeedBMW 1 Series
F20 118d
ManchesterCold-start rattle5
enquiries
Updated MonthlyBMW 1 Series
F20 M140i
LondonCooling system inspection3
enquiries
Updated MonthlyBMW 1 Series
F20 120i
BirminghamPre-purchase inspection3
enquiries
Updated MonthlyMost Requested Engines (2025)
Most Requested Variants
Average Replacement Cost
£4,200
reconditioned, supply only
[BMW-QUOTE]
Most Common Failures
Most Requested Engines (2025)
Most Requested Variants
Average Replacement Cost
£4,200
reconditioned, supply only
[BMW-QUOTE]
Most Common Failures
Scope note: All variants listed are F20 (5-door) and F21 (3-door) 1 Series. The 116d EfficientDynamics Edition (2012–2015) used a 1.6-litre N47 diesel rather than the 2.0-litre. M135i (2012–2016) used the N55 six-cylinder; M140i (2016–2019) used the B58 six-cylinder. Post-LCI (2015–2019) models switched from N13/N20/N47 to B38/B48/B47/B58 engines.
Most Requested Engines (2025)
Most Requested Variants
Average Replacement Cost
£4,200
reconditioned, supply only
[BMW-QUOTE]
Most Common Failures
Most Requested Engines (2025)
Most Requested Variants
Average Replacement Cost
£4,200
reconditioned, supply only
[BMW-QUOTE]
Most Common Failures
Most Requested Engines (2025)
Most Requested Variants
Average Replacement Cost
£4,200
reconditioned, supply only
[BMW-QUOTE]
Most Common Failures
Live FeedBMW 1 Series
F20 118d
ManchesterCold-start rattle5
enquiries
BMW 1 Series
F20 M140i
LondonCooling system inspection3
enquiries
BMW 1 Series
F20 120i
BirminghamPre-purchase inspection3
enquiries
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