How much does a BMW X4 M40d engine replacement cost in the UK?

A reconditioned B57 engine typically costs £6,000–£10,000 supply only depending on the year, with the 340 bhp facelift version sitting at £7,000–£12,000. Fitting adds £1,200–£1,800. Use our calculator for a figure specific to your car.

Is the BMW X4 M40d engine reliable?

The B57 is rated ★★★☆☆. It's a powerful and refined engine, but it has known weak points: HPFP failure (especially on 2018–2020 cars), timing chain tensioner wear (addressed by BMW Service Bulletin SWE-19-07), turbocharger wear and actuator faults, and EGR carbon buildup. Diligent maintenance is essential.

What are the common problems with the BMW X4 M40d?

HPFP failure (early cars), timing chain tensioner wear, turbocharger wear and actuator faults, and EGR carbon buildup are the most common. The HPFP is the most critical - if it fails catastrophically, it can destroy the entire fuel system and engine.

Is it worth replacing a BMW X4 M40d engine, or should I scrap the car?

Depends on vehicle value. Against a well-kept G02 X4 M40d worth £20,000–£35,000, an £8,000 recon is a manageable 23–40% of the car's value - worth it for a well-maintained example. Given the X4 M40d's strong retained values, replacement is usually viable.

How do I find my BMW X4 M40d engine code?

Listed on the VIN plate and vehicle documentation. The X4 M40d uses the B57 3.0-litre twin-turbo diesel engine. Tell us your registration date and we'll confirm it for free.

Can I repair the B57's timing chain, or does it need replacement?

Yes - if caught early. A preventative chain and tensioner replacement with reinforced units (£1,500–£3,000) is far cheaper than a catastrophic chain snap (£6,000–£12,000 engine replacement). BMW Service Bulletin SWE-19-07 addresses this issue - ensure any used car has had this work completed.

BMW X4 M40d2018–presentB57 3.0 Twin-Turbo Diesel

BMW X4 M40d Engine Replacement — Compare Prices & Get Quotes

Get quotes today from trusted UK BMW M40d specialists. Compare reconditioned, rebuilt and used B57 engines for the high-performance diesel SUV coupé - supply & fit available nationwide.

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BMW X4 M40d Engines - from £4,500 to £12,000Code: B57D30

BMW X4 M40d Engines - from £4,500 to £12,000· Code: B57D30

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The X4 M40d THROUGH TIME - Era Map

Four generations. Four eras. One guide to reliability, costs and what really matters.

Era Note

The original M40d - B57 with 326 bhp; HPFP, timing chain and turbo actuator are the main watchpoints.

GenerationYearsEngine CodeReliabilityRecon CostEra Note

G02

2018–2023B57D30T0 (326 bhp)★★★☆☆ [NEWLY ASSIGNED - see Data Note]£6,000–£10,000 [PLACEHOLDER - confirm vs cost sheet]The original M40d - B57 with 326 bhp; HPFP, timing chain and turbo actuator are the main watchpoints.

G02

2024–presentB57D30B (340 bhp + MHEV)★★★☆☆ [NEWLY ASSIGNED - see Data Note]£7,000–£12,000 [PLACEHOLDER - confirm vs cost sheet]Facelift M40d - 340 bhp with 48V mild-hybrid; same B57 architecture with updated calibration.

Why use this era map?

Every cost guide, reliability rating and engine code on this page is aligned to the data above. This keeps everything consistent and trustworthy.

Real UK Cost Data

Verified Reliability

Expert Insights

Updated for 2025

BMW X4 M40d Engine Replacement Costs

Supply Only£6,000–£10,000

Fitted (Indie)£7,200–£11,500

Warranty12–24 months

Best ForMost owners - best cost/warranty balance

Engine TypeSupply OnlyFitted (Indie)WarrantyBest For

Used Engine£4,500–£7,000£5,600–£8,5003–6 monthsBudget priority; vehicle under £15,000

Reconditioned Engine£6,000–£10,000£7,200–£11,50012–24 monthsMost owners - best cost/warranty balance

Rebuilt Engine£8,000–£12,000£9,200–£13,50012–24 monthsLong-term ownership; 3+ year horizon

Main Dealer New£15,000–£20,000£17,000–£23,00024–36 monthsInsurance jobs, warranty claims

Labour estimate: Fitting an X4 M40d engine typically takes 14–18 hours at £65–£95/hr (independent) or £110–£160/hr (London/SE dealer).

Common Problems With BMW 320d Engines

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BMW X4 M40d - Repair, Buy, or Replace?

Every 320d has a story. Make the right call with clear data, real-world costs, and honest guidance from UK specialists.

BMW X4 M40d - Repair, Buy, or Replace?

Every 320d has a story. Make the right call with clear data, real-world costs, and honest guidance from UK specialists.

Can It Be Repaired?

ProblemRepairable?Typical CostWhen It Makes SenseHPFP failure (B57 - early cars)✅ Yes£1,500–£3,000Replace with upgraded pump and revised camshaft lobes; catch it before debris destroys the engineTiming chain tensioner wear (B57)✅ Yes£1,500–£3,000Replace with reinforced units per BMW Service Bulletin SWE-19-07Turbocharger wear and actuator faults (B57)✅ Yes£1,500–£4,000Specialist refurbishment or replacement; catch it before engine damageEGR carbon buildup (B57)✅ Yes£400–£1,200Regular cleaning; use quality fuel and motorway runs to preventSnapped timing chain❌ Usually NoEngine replacementPiston-valve contact means little is left to repair

Buying This X4 M40d? Check These First

Buy If

Full BMW service history with documented oil-change intervals
HPFP replaced with upgraded unit on early cars (2018–2020)
Timing chain tensioner replaced with reinforced unit per Service Bulletin SWE-19-07
2024+ facelift for the 340 bhp output and mild-hybrid system
Evidence of regular motorway use (to prevent EGR carbon buildup)

Avoid If

Long crank times or hesitation - potential HPFP failure risk
Cold-start rattle with no chain history - timing chain tensioner warning
Loss of power or turbo noise without diagnosis
Poor service history - the B57 is unforgiving of neglect

Closing Verdict

The X4 M40d is a remarkable performance diesel - 326–340 bhp from a six-cylinder twin-turbo. But the B57 has known weak points: HPFP failure (especially early cars), timing chain tensioner wear, and turbo issues. Buy on documented history and proof of preventative maintenance. If you're replacing, a reconditioned unit with upgraded HPFP and timing chain components is essential.

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Buying Checklist

Before you buy a used BMW X4 M40d (or before you commit to an engine replacement), check these:

Cold Start

Listen for rattle on startup (timing chain tensioner wear)

Service History

Including which engine era (B57 is the only M40d engine - verify this before purchase)

HPFP Health

Long crank times? Hesitation? HPFP failure is a critical risk on early cars

Turbo Health

Test acceleration through the rev range; any lag, whistling, or uneven power delivery?

EGR System

Any loss of power or rough idle? EGR carbon buildup is common

Oil Consumption

Does it use more than 1L per 5,000 miles? If so, investigate

Engine Warning Light

Have codes been read? Any unresolved issues?

MOT History

Check for emissions-related failures; often point to EGR or DPF problems

Buy smart. Drive with confidence.

A few checks today can save thousands tomorrow. Use this checklist to avoid the most common 320d pitfalls.

Buy smart. Drive with confidence.

A few checks today can save thousands tomorrow. Use this checklist to avoid the most common 320d pitfalls.

BMW 320d Engine Codes

B57D30T0

Years2018–2023

Power326 bhp / 680 Nm

2025 Enquiries- (pattern data)

Avg. Recon Cost£6,000–£10,000 [PLACEHOLDER]

Engine CodeYearsPower2025 EnquiriesAvg. Recon Cost

B57D30T02018–2023326 bhp / 680 Nm- (pattern data)£6,000–£10,000 [PLACEHOLDER]

B57D30B2024–present340 bhp / 700 Nm- (pattern data)£7,000–£12,000 [PLACEHOLDER]

Technical Specs

B57D30T0

Displacement2,993cc

Cylinders6-cylinder inline

Compression Ratio16.5:1

Fuel SystemCommon-rail direct injection

TurbochargerTwin turbo (B57D30T0)

Market Intelligence

Most Common Failure

HPFP failure and timing chain tensioner wear

55%

of B57 enquiries

[PATTERN DATA]

Average Enquiry Mileage

55,000

miles

[PATTERN DATA]

Average Replacement Cost

£8,000

reconditioned, supply only

[PLACEHOLDER - confirm vs cost sheet]

Most Requested Engine Code

B57D30

[BMW-VERIFIED]

Peak Enquiry Season

Winter

cold starts expose chain and HPFP issues

[PATTERN DATA]

Regional Demand

London22%

South East20%

South West14%

PATTERN DATA

Regional Demand Breakdown

22%London

20%South East

BMW 320d - Frequently Asked Questions

All prices are indicative UK market ranges based on historical quote data from our network of engine specialists. Actual costs vary by variant, engine code, damage severity and workshop location. Use our free comparison tool to get tailored quotes. Every engine supplied through EnginesMarket carries a minimum 12-month unlimited-mileage warranty - always confirm terms with your chosen supplier.

Find the best BMW X4 M40d engine replacement UK drivers rely on. Compare prices from trusted specialists on EnginesMarket today and get back on the road with confidence.

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100% Free

No hidden fees

No Obligation

Get quotes with zero pressure

UK Specialists

20+ vetted experts

12-Month Warranty

As standard

Nationwide Delivery

Supply & fit available