BMW X3 M40i2018–present1 Engine Generation (2 Power Levels)

BMW X3 M40i Engine Replacement —Compare Prices &
Get Quotes

Name: BMW X3 M40i UK Engine Enquiry Data 2025
Creator: BMWEngines.uk

Get quotes today from trusted UK BMW X3 M40i specialists. The 3.0-litre B58 turbocharged inline-six is one of BMW's most celebrated modern engines — compare reconditioned, rebuilt and used engines with supply & fit available nationwide.

Supply &Fit Available
12-MonthWarranty
NationwideDelivery
20+Specialists

Supply &Fit Available
12-MonthWarranty
NationwideDelivery
20+Specialists

BMW X3 M40i Engines — from £1,500 to £13,000Engine codes: B58B30O0, B58B30O1

Instant Quotes
No Obligation
100% Free
Reconditioned
Rebuilt
Used
Supply & Fit Available
UK-Wide Network

Instant Quotes
No Obligation
100% Free
Reconditioned
Rebuilt
Used
Supply & Fit Available
UK-Wide Network

BMW X3 M40i — Which Engine Does Your Car Actually Have?

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

Era Note

3.0L turbo inline-six — 355–365 hp, 500 Nm. Plastic oil filter housing and coolant connector weak points

Era Note

3.0L turbo with 48V MHEV — 382 hp, 500 Nm. Same B58 family, revised ECU calibration

Generation	Years	Engine Code	Reliability	Recon Cost (Guide)	Era Note
G01 (pre-LCI)	2018–2021	B58B30O0(B58TU1)		£4,000–£6,500[PLACEHOLDER]	3.0L turbo inline-six — 355–365 hp, 500 Nm. Plastic oil filter housing and coolant connector weak points
G01 LCI	2021–present	B58B30O1 / B58B30B		£4,000–£6,500[PLACEHOLDER]	3.0L turbo with 48V MHEV — 382 hp, 500 Nm. Same B58 family, revised ECU 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 UKCost Data
VerifiedReliability
ExpertInsights
Updated for2025

BMW X3 M40i Engine Replacement Costs

Supply Only£4,000 – £6,500
Fitted (Indie)£6,000 – £8,500
Warranty12–24 months
Best ForMost owners — best cost/warranty balance

Engine Type	Supply Only	Fitted (Indie)	Warranty	Best For
Used Engine	£1,500 – £3,500	£2,500 – £5,000	1–6 months	Budget priority; lower-mileage donor
Reconditioned Engine	£4,000 – £6,500	£6,000 – £8,500	12–24 months	Most owners — best cost/warranty balance
Rebuilt Engine	£5,000 – £8,500	£7,000 – £10,000	12–24 months	Long-term ownership; 3+ year horizon
Main Dealer New	£9,000 – £13,000+	£11,000 – £15,000+	24–36 months	Insurance jobs, warranty claims

Labour estimate: Fitting an X3 M40i engine typically takes 12–16 hours at £65–£95/hr (independent) or £110–£160/hr (London/SE dealer).

Compare X3 M40i engine prices from UK specialists

Common Problems With BMW X3 M40i Engines

1. Oil Filter Housing Failure(Plastic Cracking)

Symptoms: Oil leaks visible around the oil filter housing, coolant leaks, low oil level warning, burning oil smell from engine bay, pooling oil under the vehicle
Typical Mileage: 60,000–100,000 miles — the plastic housing has an average lifespan of around eight years
Repair Cost: £800–£2,500 (oil filter housing replacement with gaskets and hardware)
Replacement Cost: £4,000–£8,500 (if ignored — coolant-oil contamination can cause engine failure)
Urgency: Check — book inspection urgently if you notice oil or coolant leaks

Our recommendation:

BMW chose to make the B58's oil filter housing out of plastic. Over time, the plastic becomes brittle from heat cycles, cracking and leaking oil, coolant, or both. BMW is facing a class action lawsuit over faulty oil filter housings that leak coolant, resulting in owners having to spend thousands of pounds in repairs. A replacement oil filter housing with labour can run from £800 to £2,500. If you notice oil spots or coolant loss, have the oil filter housing inspected immediately — catching this early prevents catastrophic engine failure.

Read the full oil filter housing failure guide → /failures/b58-oil-filter-housing/ [NEW FAILURE PAGE NEEDED] /failures/n55-valve-cover-oil-leak

1. Oil Filter Housing Failure(Plastic Cracking)

Symptoms: Oil leaks visible around the oil filter housing, coolant leaks, low oil level warning, burning oil smell from engine bay, pooling oil under the vehicle
Typical Mileage: 60,000–100,000 miles — the plastic housing has an average lifespan of around eight years
Repair Cost: £800–£2,500 (oil filter housing replacement with gaskets and hardware)
Replacement Cost: £4,000–£8,500 (if ignored — coolant-oil contamination can cause engine failure)
Urgency: Check — book inspection urgently if you notice oil or coolant leaks

Our recommendation:

Read the full oil filter housing failure guide → /failures/b58-oil-filter-housing/ [NEW FAILURE PAGE NEEDED] /failures/n55-valve-cover-oil-leak

2. Coolant System Leaks(Plastic Connector Failure)

Symptoms: Low coolant warning light, coolant level dropping, visible coolant residue under the vehicle or around the engine bay, significant pressure released when opening the low temperature cooling system reservoir
Typical Mileage: Can occur from 40,000 miles — heat cycling and hydrolysis weaken plastic components
Repair Cost: £300–£800 (coolant hose connector replacement, thermostat housing, or water pump)
Replacement Cost: £4,000–£8,500 (if ignored — overheating can cause catastrophic engine damage)
Urgency: Check — book inspection urgently if coolant level drops frequently

Our recommendation:

One of the most frequent failure points on the B58 is the coolant hose connector behind the heat management module. The OE plastic connector is prone to cracking and leaks due to hydrolysis and repeated heat cycles. An upgraded aluminium connector eliminates this failure point. Coolant leaks are common across the B58 platform. If you're topping up coolant regularly, have the system pressure-tested and inspect the plastic connectors behind the intake manifold.

Read the full coolant leak guide → /failures/b58-coolant-leak/ [NEW FAILURE PAGE NEEDED] /failures/m54-cooling-system

3. Valve Cover Gasket Oil Leaks

Symptoms: Burning oil smell from the engine bay, visible oil residue around the valve cover perimeter, oil spots under the car, low oil level warning
Typical Mileage: 60,000–100,000 miles — gaskets harden and crack from heat cycling
Repair Cost: £400–£1,200 (valve cover gasket replacement)
Replacement Cost: N/A — repair only (does not progress to engine replacement if addressed)
Urgency: Monitor — book inspection if you notice oil spots or burning smell

Our recommendation:

One of the most frequently reported issues on the B58 is oil leaks from the valve cover gasket and oil filter housing. The rubber gasket deteriorates from heat cycling and age, leading to oil leaks that can cause low oil levels and potential engine damage if not addressed promptly. Valve cover gasket leaks are "manageable expenses" when caught early. If you notice a burning smell or oil spots, have the gasket inspected promptly.

Read the full oil leak guide → /failures/b58-oil-leaks/ [NEW FAILURE PAGE NEEDED] /failures/n55-valve-cover-oil-leak

4. VANOS Solenoid Wear

Symptoms: Power loss during acceleration, rough idle, slow throttle response, check engine light with VANOS-related fault codes
Typical Mileage: 50,000–75,000 miles (80,000–120,000 km) — O-rings deteriorate from heat and oil contamination
Repair Cost: £300–£600 (VANOS solenoid replacement with O-rings)
Replacement Cost: N/A — repair only (does not progress to engine replacement if addressed)
Urgency: Monitor — book inspection if symptoms develop

Our recommendation:

The VANOS solenoid's rubber O-ring deteriorates over time due to heat and oil contamination. BMW recommends replacing VANOS seals every 80,000 km as preventive maintenance. Symptoms include noticeable power loss, rough idle, and slow throttle response. If you experience these issues, have the VANOS solenoids inspected and replaced with updated BMW parts. This is a relatively straightforward repair that can restore full engine performance.

Read the full VANOS failure guide /failures/vanos-solenoid-failure/

Weighing Your Options?

Compare Specialist Quotes When You're Ready

20+ vetted BMW specialists, every X3 M40i engine covered, with a 12-month warranty as standard.

See X3 M40i Engine Options

X3 M40i — Repair, Buy, or Replace?

Not every issue means a new engine.Here’s what can be repaired, when it makes sense, and what to check before you buy.

Can It Be Repaired?

Problem	Repairable?	Typical Cost	When It Makes Sense
Oil filter housing failure	Yes	£800 – £2,500	Catch early to prevent coolant-oil contamination
Coolant system plastic connector	Yes	£300 – £800	Upgraded aluminium connector is a permanent fix
Valve cover gasket leak	Yes	£400 – £1,200	Straightforward repair on any well-maintained example
VANOS solenoid failure	Yes	£300 – £600	Component replacement — restores full performance
Water pump failure	Yes	£500 – £1,000	Preventative replacement at 60,000–80,000 miles recommended

ProblemRepairable? · Typical Cost

Oil filter housing failure

Yes£800 – £2,500

Catch early to prevent coolant-oil contamination

Coolant system plastic connector

Yes£300 – £800

Upgraded aluminium connector is a permanent fix

Valve cover gasket leak

Yes£400 – £1,200

Straightforward repair on any well-maintained example

VANOS solenoid failure

Yes£300 – £600

Component replacement — restores full performance

Water pump failure

Yes£500 – £1,000

Preventative replacement at 60,000–80,000 miles recommended

Buying This X3 M40i? Check These First

Buy if:

Full service history with BMW-approved oil changes (BMW Longlife-01 FE or LL-04)
Evidence of oil filter housing inspection or replacement — this is a known B58 weakness
Upgraded aluminium coolant connectors fitted — eliminates the plastic connector failure point
Remaining manufacturer warranty — these are complex performance vehicles

Avoid if:

Oil or coolant leaks around the oil filter housing — this is a ticking time bomb
Frequent coolant top-ups with no documented fix — plastic connectors are a known weakness
Check engine light with VANOS-related fault codes
Poor service history — the B58 is reliable but needs proper maintenance

Closing verdict

The X3 M40i's B58 is one of BMW's finest modern engines — a 3.0-litre turbocharged inline-six with up to 382 hp that delivers effortless performance and genuine character. The B58 is "known for minimal major issues when properly maintained"and is "widely considered one of the finest engines BMW has ever produced". However, it has well-documented weak points: plastic oil filter housings that crack and leak, plastic coolant connectors that fail, valve cover gasket oil leaks, and VANOS solenoid wear. Buy with full service history and evidence of preventative maintenance, and you'll have one of the most rewarding performance SUVs on the road.

Don’t Guess. Compare.

Get real quotes from vetted UK specialists and make the right call for your X3 M40i.

Compare X3 M40i engine prices before you buy

20+ Vetted SpecialistsUK Network
12-Month Warrantyas Standard
Nationwide Delivery& Collection
Transparent PricingNo Hidden Fees
Thousands of X3 M40iOwners Helped

Buying Checklist

Before you buy a used BMW X3 M40i (or before you commit to an engine replacement), check these:

1. Oil Filter Housing
Inspect for oil or coolant leaks around the oil filter housing — this is the most common B58 failure
2. Coolant Level
Check for frequent top-ups; inspect for leaks around the heat management module
3. Oil Leaks
Look for oil residue around the valve cover perimeter — burning smell indicates gasket failure
4. Cold Start
Listen for any unusual rattling or ticking (B58 timing chain is generally robust, but check anyway)
5. VANOS Health
Any power loss, rough idle, or hesitation? Check for fault codes
6. Service History
Including the B58 engine and confirmed BMW-approved oil changes
7. Engine Warning Light
Have codes been read? Look for VANOS or cooling system codes
8. MOT History
Check for emissions-related failures

Why this matters

A 10-minute check now can save you thousands later. The right X3 M40i is a superb long-term car — the wrong one can be expensive fast.

Buying Checklist

Before you buy a used BMW X3 M40i (or before you commit to an engine replacement), check these:

1
Oil Filter Housing
Inspect for oil or coolant leaks around the oil filter housing — this is the most common B58 failure
2
Coolant Level
Check for frequent top-ups; inspect for leaks around the heat management module
3
Oil Leaks
Look for oil residue around the valve cover perimeter — burning smell indicates gasket failure
4
Cold Start
Listen for any unusual rattling or ticking (B58 timing chain is generally robust, but check anyway)
5
VANOS Health
Any power loss, rough idle, or hesitation? Check for fault codes
6
Service History
Including the B58 engine and confirmed BMW-approved oil changes
7
Engine Warning Light
Have codes been read? Look for VANOS or cooling system codes
8
MOT History
Check for emissions-related failures

Buy smart. Drive with confidence.

A few checks today can save thousands tomorrow. Use this checklist to avoid the most common X3 M40i pitfalls.

Engine Codes

This table's rows match Section 1B's Era Map exactly.

B58B30O0 (B58TU1)

Years: 2018–2021
Power: 355–365 hp (265–270 kW) / 500 Nm
2025 Enquiries: —(pattern data)
Avg. Recon Cost: £4,000–£6,500[PLACEHOLDER]

Engine Code	Years	Power	2025 Enquiries	Avg. Recon Cost
B58B30O0 (B58TU1)	2018–2021	355–365 hp (265–270 kW) / 500 Nm	—(pattern data)	£4,000–£6,500[PLACEHOLDER]
B58B30O1 / B58B30B	2021–present	382 hp (285 kW) / 500 Nm	—(pattern data)	£4,000–£6,500[PLACEHOLDER]

Technical SpecsB58

Displacement: 2,998 cc (3.0L)
Cylinders: 6-cylinder inline
Bore: 82 mm / Stroke: 94.6 mm
Cylinder Block: Closed-deck aluminium
Cylinder Head: Aluminium
Valvetrain: DOHC, 4 valves per cylinder, Valvetronic, Double VANOS
Valvetrain Drive: Chain
Compression Ratio: 11.0:1
Fuel System: Direct injection
Turbocharger: Single twin-scroll turbo
0-62 mph: 4.8 seconds
Top Speed: 155 mph (limited)

Compare X3 M40i engine prices for your BMWGet quotes from trusted UK specialists in minutes.

Market Intelligence

Real data from thousands of X3 M40i enquiries in 2025.

Most Common FailureOil filter housing failure

Plastic housing cracks and leaks oil or coolant; average lifespan around eight years

Average Enquiry Mileage

40,000–80,000

miles

[PATTERN DATA]

Average Replacement Cost

£4,500–£5,500

reconditioned, supply only

[PLACEHOLDER]

Most Requested Engine Code

B58B30O0

[PATTERN DATA]

Peak Enquiry Season

Summer

Cooling system issues become more apparent

[PATTERN DATA]

Regional Demand

London: 22%
South East: 18%
North West: 12%
Other Regions: 48%

[PATTERN DATA]

Regional Demand Breakdown

22%London18%South East12%North West48%Other Regions

Frequently Asked Questions

A reconditioned X3 M40i (B58) engine typically costs £4,000–£6,500 supply only. Fitting adds £2,000–£3,000 depending on location and workshop rates. A replacement B58B30B motor costs on average £5,156 in good condition, with new or reconditioned engines up to £7,944. Main dealer new engines start from £9,000–£13,000+ supply only. Use our calculator for a figure specific to your car.

Yes — the B58 is widely regarded as one of BMW's most reliable modern engines. It's "known for minimal major issues when properly maintained"and is "widely considered one of the finest engines BMW has ever produced". However, common issues include plastic oil filter housing failure, coolant system leaks from plastic connectors, valve cover gasket oil leaks, and VANOS solenoid wear.

The main known issues are: (1) Oil filter housing failure — plastic housing cracks and leaks oil or coolant; average lifespan around eight years, (2) Coolant system leaks from plastic connectors behind the heat management module, (3) Valve cover gasket oil leaks, and (4) VANOS solenoid wear — causing power loss and rough idle.

Depends on vehicle value and condition. Against a well-kept £20,000–£40,000 X3 M40i, a £4,500–£6,500 recon is 10–30% of the car's value — worth it given the X3 M40i's strong retained values. The B58's robust reliability means that with proper maintenance, these engines can achieve very high mileages.

The X3 M40i uses the B58 engine family. Pre-LCI cars (2018–2021) have B58B30O0 (355–365 hp); LCI cars (2021–present) have B58B30O1 or B58B30B (382 hp with 48V MHEV). The engine code is stamped on the cylinder block. Tell us your registration and we'll confirm it for free.

Unlike BMW's earlier turbo engines (N54, N55), the B58's timing chain is not a common failure point. The B58TU1 introduced a redesigned one-piece timing chain arrangement. The chain is designed to last the life of the engine and does not require routine replacement. However, VANOS solenoid issues can affect timing performance.

Disclaimer: 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.

Why UK BMW X3 M40i Owners Trust BMWEngines.uk

Trusted X3 M40i Engine Suppliers
every garage and engine rebuilder in our network is vetted, rated and reviewed by real X3 M40i owners, across both B58TU1 and B58TU2 variants, as part of the Engine Finders network.
Compare X3 M40i Engine Replacement Companies
see prices, warranty terms and supply & fit options side-by-side before you commit.
UK Engine Replacement Services for X3 M40i
supply-only or full supply & fit available nationwide, covering every G01 X3 M40i since 2018.

Find the best BMW X3 M40i engine replacement UK drivers rely on.

Compare prices from trusted specialists on EnginesMarket today and get back on the road with confidence.

Explore BMW X3 M40i Engine Quotes

100% FreeNo hidden fees
No ObligationGet quotes with zero pressure
UK Specialists20+ vetted experts
12-Month WarrantyAs standard
Nationwide DeliverySupply & fit available

BMW X3 M40i Engine Replacement —Compare Prices &Get Quotes

BMW X3 M40i — Which Engine Does Your Car Actually Have?

BMW X3 M40i Engine Replacement Costs

Common Problems With BMW X3 M40i Engines

1. Oil Filter Housing Failure(Plastic Cracking)

2. Coolant System Leaks(Plastic Connector Failure)

3. Valve Cover Gasket Oil Leaks

4. VANOS Solenoid Wear

1. Oil Filter Housing Failure(Plastic Cracking)

2. Coolant System Leaks(Plastic Connector Failure)

3. Valve Cover Gasket Oil Leaks

4. VANOS Solenoid Wear

Weighing Your Options?

X3 M40i — Repair, Buy, or Replace?

Can It Be Repaired?

Buying This X3 M40i? Check These First

Buying Checklist

Buying Checklist

Engine Codes

Market Intelligence

Regional Demand Breakdown

Frequently Asked Questions

Why UK BMW X3 M40i Owners Trust BMWEngines.uk

Trusted X3 M40i Engine Suppliers

Compare X3 M40i Engine Replacement Companies

UK Engine Replacement Services for X3 M40i

BMW X3 M40i Engine Replacement —Compare Prices &
Get Quotes