BMW X4 F26Coupé SUV2014–2018

BMW X4 F26 Engines -The Complete UK Guide

Every engine fitted to the first-generation X4 F26 – from the 2.0-litre N20 four-cylinder petrol and B47 diesel to the 3.0-litre N55 straight-six and the M40i's 360 hp B58. Real UK replacement costs, honest reliability data, and the N20 timing chain guide weakness that defines this generation's ownership story. Backed by real UK F26 enquiries in 2025 [BMW-VERIFIED].

Explore F26 Engines
F26Enquiries (2025)BMW-VERIFIED
Coupé SUV
8Engine Codes
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BMW X4 F26 Engine Codes -The Complete Database

Every engine fitted to the X4 F26 – from the entry-level four-cylinder to the range-topping M40i.

Engine CodeFuelPowerYearsReliabilityEnquiriesAvg. Recon Cost
N20B20AN20Petrol184 hp (135 kW)2014–2018★★★☆☆ [PROVISIONAL]-(pattern data)£1,800–£4,000 [BMW-QUOTE]
N20B20AN20Petrol245 hp (180 kW)2014–2018★★★☆☆ [PROVISIONAL]-(pattern data)£2,000–£4,500 [BMW-QUOTE]
N55B30AN55Petrol306 hp (225 kW)2014–2018★★★★☆ [PROVISIONAL]-(pattern data)£3,500–£6,000 [BMW-QUOTE]
B58B30M1B58Petrol360 hp (265 kW)2016–2018★★★★½ [PROVISIONAL]-(pattern data)£4,000–£7,000 [BMW-QUOTE]
N47D20AN47Diesel190 hp (140 kW)2014–2015★★★☆☆ [PROVISIONAL]1,450 [EM-VERIFIED] (platform-wide)£2,800–£5,000 [BMW-QUOTE]
B47D20AB47Diesel190 hp (140 kW)2015–2018★★★★☆ [PROVISIONAL]-(pattern data)£2,800–£5,000 [BMW-QUOTE]
N57D30AN57Diesel258 hp (190 kW)2014–2018★★★★☆ [PROVISIONAL]830 [EM-VERIFIED] (platform-wide)£4,500–£7,000 [BMW-QUOTE]
N57D30BN57Diesel313 hp (230 kW)2014–2018★★★★☆ [PROVISIONAL]-(pattern data)£5,000–£8,000 [BMW-QUOTE]
BMW 3 Series E90

Overview

BMW X4 F26 -Overview

The BMW X4 F26, produced from July 2014 to March 2018, is the first-generation X4 and BMW's second "Sports Activity Coupé" (SAC) after the X6.

Built on the BMW L7 platform shared with the F25 X3, the X4 is 23 mm longer and 37 mm taller than the X3 it is based on. It features a sloping coupé-style roofline that trades some practicality for sportier styling, with all models featuring xDrive all-wheel drive and an 8-speed automatic transmission.

Key Facts

Platform

BMW L7 (F25/F26)

Predecessor

None (X4 introduced as new model line)

Successor

BMW X4 G02 (2018–present)

Sibling body styles in this generation

None (F26 is the sole first-generation X4 body code)

Market Intelligence

The F26 generated real UK engine enquiries in 2025 [BMW-VERIFIED], with the N20 petrol and N47/B47 diesel accounting for the majority of demand as these cars enter their second and third ownership cycles.

Best & Worst Engines

B47D20A (xDrive20d, 2015–2018) – "The B47 is a significant improvement over the N47 – timing chain issues are less prevalent, the EGR cooler recall has been addressed, and it's smoother and cleaner. It's the diesel to choose for peace of mind." engine

Best Diesel Overall

B47D20A (xDrive20d, 2015–2018) – "The B47 is a significant improvement over the N47 – timing chain issues are less prevalent, the EGR cooler recall has been addressed, and it's smoother and cleaner. It's the diesel to choose for peace of mind."

Who it's for: buyers who want diesel economy without the N47's timing chain anxiety.

B58B30M1 (X4 M40i, 2016–2018) – "The B58 straight-six delivers 360 hp of silky-smooth power with proven reliability and a sonorous exhaust note. It's a significant step up from the N55 – water pump and cooling system are the only real demands. This engine transforms the X4." engine

Best Petrol Overall

B58B30M1 (X4 M40i, 2016–2018) – "The B58 straight-six delivers 360 hp of silky-smooth power with proven reliability and a sonorous exhaust note. It's a significant step up from the N55 – water pump and cooling system are the only real demands. This engine transforms the X4."

Who it's for: buyers who want effortless performance and the best engine the F26 ever received.

N20B20A (xDrive20i/28i, pre-2015) – "The N20 four-cylinder carries a significant timing chain guide weakness – failure can occur as early as 60,000 miles, leading to a £4,000+ engine replacement. Cold-start rattle is the warning sign. The N20 is the F26's biggest risk." engine

Highest Risk

N20B20A (xDrive20i/28i, pre-2015) – "The N20 four-cylinder carries a significant timing chain guide weakness – failure can occur as early as 60,000 miles, leading to a £4,000+ engine replacement. Cold-start rattle is the warning sign. The N20 is the F26's biggest risk."

Who it's for: only buyers who have confirmed chain guide replacement or are budgeting for it.

N57D30B (xDrive35d) – "The twin-turbo diesel produces 313 hp and 630 Nm of torque – impressive, but the complex turbo system and EGR cooler issues can lead to bills exceeding £5,000. This is not an engine for the faint-hearted." engine

Most Expensive Failure

N57D30B (xDrive35d) – "The twin-turbo diesel produces 313 hp and 630 Nm of torque – impressive, but the complex turbo system and EGR cooler issues can lead to bills exceeding £5,000. This is not an engine for the faint-hearted."

Who it's for: buyers who want diesel performance and accept the associated running costs.

B58B30M1 (X4 M40i, 2016–2018) – "The M40i delivers 360 hp with none of the N20's timing chain anxiety. It's smoother, more reliable and more desirable than any other F26 engine – and values reflect that. The sweet spot of the range." engine

Best Value

B58B30M1 (X4 M40i, 2016–2018) – "The M40i delivers 360 hp with none of the N20's timing chain anxiety. It's smoother, more reliable and more desirable than any other F26 engine – and values reflect that. The sweet spot of the range."

Who it's for: buyers who want the best F26 money can buy.

N55B30A (xDrive35i, 2014–2018) – "The 306 hp straight-six is often overlooked in favour of the M40i, but it delivers effortless power with proven N55 reliability and lower running costs than the B58. It's the sensible performance choice for F26 buyers." engine

Most Overlooked

N55B30A (xDrive35i, 2014–2018) – "The 306 hp straight-six is often overlooked in favour of the M40i, but it delivers effortless power with proven N55 reliability and lower running costs than the B58. It's the sensible performance choice for F26 buyers."

Who it's for: buyers who want six-cylinder performance without the M40i premium.

BMW X4 F26 -Ownership Economics

EngineTypical MileageCommon Major FailureRepair Cost (Specialist)Replacement Cost (Recon)Ownership Verdict
N20B20A (20i/28i)60k–100kTiming chain guides£800–£1,500£1,800–£4,500
High Risk – chain failure is a grenade; budget for replacement.
N55B30A (35i)60k–100kWater pump, HPFP£500–£1,200£3,500–£6,000
Solid – proven six, minor cooling issues.
B58B30M1 (M40i)60k–100kWater pump, cooling£400–£800£4,000–£7,000
Best Petrol – BMW's finest modern six.
N47D20A (20d, 2014–2015)60k–120kTiming chain, EGR cooler£600–£1,200£2,800–£5,000
Watch – timing chain issues; avoid without history.
B47D20A (20d, 2015–2018)60k–120kEGR cooler, DPF£400–£800£2,800–£5,000
Best Diesel – improved chain design; reliable.
N57D30A (30d)80k–150kEGR cooler, turbo£500–£1,000£4,500–£7,000
Solid – proven diesel six.
N57D30B (35d)60k–100kTurbo, EGR cooler£800–£2,000£5,000–£8,000
Expensive – twin-turbo complexity.

The F26 rule

A £2,800–£5,000 B47/N47 recon against a £6,000–£15,000 F26 sits at 19–83% of the car's value. On a sub-£8,000 diesel F26, that brushes our 70% BMW threshold – we'll honestly tell you to walk away unless the car has documented chain work. Against a £12,000+ low-mileage example, the same recon drops to a routine 23–42% – a repair decision, not a financial one. For the M40i, a £7,000 B58 replacement is well within the value of a £20,000+ example.

Key Takeaways

  • Which F26 Costs Least To Own?

    B47D20A (xDrive20d, post-2015) – proven diesel, reduced timing chain risk.

  • Which F26 Costs Most To Own?

    N57D30B (xDrive35d) – twin-turbo complexity and premium running costs.

  • Which F26 Is Best Value?

    B58B30M1 (X4 M40i) – the best engine in the range, with values to match.

Common Problems

F26 Engine Replacement Costs -By Engine and Condition

Core Variants

Diesel & Petrol Lineup

Diesel Variants

xDrive20dxDrive30dxDrive35dM40d

Petrol Variants

xDrive20ixDrive28ixDrive35iX4 M40i

Scope note: All variants listed are F26 only. The G02 X4 (2018–present) is the successor generation with its own engine line-up – see the G02 Generation Page for those specifications. All F26 models feature xDrive all-wheel drive and an 8-speed automatic transmission as standard.

Market Intelligence

Most Requested E90 Engines (2025)

  1. 1.1. B47D20A/N47D20A (xDrive20d) – diesel enquiries dominate the volume
  2. 2.2. B58B30M1 (X4 M40i) – performance petrol enquiries
  3. 3.3. N20B20A (xDrive20i/28i) – timing chain-related enquiries [PATTERN DATA].

Most Requested E90 Variants

  1. 1.1. xDrive20d
  2. 2.2. X4 M40i
  3. 3.3. xDrive30d [PATTERN DATA].

Average E90 Replacement Cost

£1,800–£8,000 supply only [BMW-QUOTE].

Most Common E90 Failures

  1. 1.1. N20 timing chain guides (petrol four)
  2. 2.2. N47 timing chain stretch (pre-2015 diesel)
  3. 3.3. EGR cooler failure (diesel)
  4. 4.4. Water pump failure (N55/B58) [PATTERN DATA].
Live Feed
VehicleLocationIssueEnquiries
BMW X4 xDrive20d (B47D20A)

BMW X4 xDrive20d (B47D20A)

Birmingham
EGR cooler recall enquiry

5

enquiries

BMW X4 M40i (B58B30M1)

BMW X4 M40i (B58B30M1)

London
Coolant loss

3

enquiries

BMW X4 xDrive20i (N20B20A)

BMW X4 xDrive20i (N20B20A)

Manchester
Cold-start rattle

3

enquiries

Updated Monthly

FAQ

BMW 3 Series E90 rear three-quarter view

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