BMW Z4 M40i Engine ReplacementCompare Prices & Get Quotes
Get quotes today from trusted UK BMW Z4 M40i engine specialists. Compare prices on reconditioned, rebuilt and used B58 turbo straight-six engines for the G29 roadster - supply & fit available nationwide.
Supply & Fit Available
12-Month Warranty
Nationwide Delivery
100+ Suppliers
From Turbo Straight-Six - from £3,500 to £7,500
Used from £2,500 · Reconditioned from £4,200 · Common codes: B58B30, B58B30M1, B58B30M2
From £2,500
Tested, bare/short engine
From £4,200
Rod bearings addressed, tested
From quote
Upgraded bearings, full teardown, revised valvetrain
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3 Simple Steps3 Simple Stepsto Finding the Best BMW Z4 M40i Replacement Engineto Finding the Best BMW Z4 M40i Replacement Engine
Most replacements completed within 3-5 days.
Variant HistoryBMW Z4 M40i - Engine History & Specs at a Glance
The BMW Z4 M40i is the flagship performance variant of the G29 Z4, launched in 2019 as the spiritual successor to the Z4M. Powered exclusively by BMW's acclaimed B58B30 3.0-litre turbocharged straight-six, it delivers 340hp in standard form and up to 382hp in later LCI variants. The B58 - widely regarded as one of BMW's most reliable modern engines - combines closed-deck construction, integrated exhaust manifold, and TwinPower turbo technology for effortless performance.
Variant HistoryBMW Z4 M40i - Engine History & Specs at a Glance
The BMW Z4 M40i is the flagship performance variant of the G29 Z4, launched in 2019 as the spiritual successor to the Z4M. Powered exclusively by BMW's acclaimed B58B30 3.0-litre turbocharged straight-six, it delivers 340hp in standard form and up to 382hp in later LCI variants. The B58 - widely regarded as one of BMW's most reliable modern engines - combines closed-deck construction, integrated exhaust manifold, and TwinPower turbo technology for effortless performance.
BMW Z4 M40i
Fuel TypePetrol (twin-turbocharged)
Engine Size3.0L (2,998cc)
Power Output Range340-382hp across the variant's historyEngine History Timeline
G29 Z4 M40i launched with B58B30 340hp, 500Nm, 8-speed automatic
B58B30M1 engine code introduced; power unchanged
Minor ECU updates for improved response
LCI facelift B58B30M2 with 382hp, 6-speed manual option introduced
present - B58B30M2 continues with 382hp 8-speed auto and 6-speed manual options
Key Specs Snapshot
Fuel TypePetrol (twin-turbocharged)Engine Size3.0L (2,998cc)Power Output Range340-382hp across the variant's historyTorque500NmYears Produced2019-presentEvery engine fitted to the BMW Z4 M40i is covered below, with UK rebuilt pricing and known failure points specific to the B58 turbo straight-six.
BMW Z4 M40i Engine Codes - Specifications & Replacement CostBMW Z4 M40i Engine Codes - Specifications & Replacement Cost
3.0L Twin-Turbo Straight-Six Petrol (2019-2020)
Power Output340hp (250kW) @ 5,000-6,500rpmTorque500Nm @ 1,600-4,500rpmDisplacement2,998ccYears Fitted2019-2020 (G29 Z4 M40i)Engine FeaturesClosed-deck aluminium block, integrated exhaust manifold, TwinPower twin-scroll turbo, direct injection
Compatible Trim Levels
- M40i
- M40i First Edition
Find your exact engine code, specs and UK replacement cost guide.
Used
Tested, ready-to-fit engine
£2,500-£4,500
Reconditioned
Addressed known issues, tested
£4,200-£6,500
Rebuilt
Full teardown, upgraded internals
£5,500-£8,500
Common Failure
PCV valve diaphragm failure (integrated into valve cover) causing whistling and oil consumption, water pump failure leading to overheating, charge pipe fragility under track conditions.
The BMW Z4 M40i's B58 turbo straight-six is widely regarded as one of BMW's most reliable modern engines, but it's not immune to wear. The most common issues - PCV diaphragm failure, water pump failure, and charge pipe fragility - are well-documented and typically occur between 50,000-80,000 miles. Every rebuilt engine supplied through EnginesMarket includes upgraded components designed to address these original failure points - plus a minimum 12-month unlimited mileage warranty.
Why the BMW Z4 M40i Whistles and Burns Oil
Affected Vehicles
BMW Z4 M40i (G29 2019-present, B58B30, B58B30M1, B58B30M2)
Typical Failure Mileage
50,000-75,000 miles (80,000 km)
Root Cause
The crankcase ventilation (PCV) system is integrated into the valve cover. The rubber diaphragm tears over time, causing excessive crankcase pressure, whistling noises, oil consumption, and oil leaks.
Why It Happens
The crankcase ventilation (PCV) system is integrated into the valve cover. The rubber diaphragm tears over time, causing excessive crankcase pressure, whistling noises, oil consumption, and oil leaks.
Dealer (parts + labour)
£1,200-£1,800
Specialist (parts + labour)
£700-£1,200
What it involves
Replace complete valve cover with integrated PCV, new gaskets, breather hoses
Suitability
Restores crankcase pressure control; 60,000+ mile lifespan
1 - 2 daysDealer (parts + labour)
£8,500-£12,000
Specialist (parts + labour)
£5,500-£8,500
What it involves
Supply & fit rebuilt B58 with upgraded valve cover and PCV components, 12-month warranty
Suitability
Required if oil consumption caused catalytic converter damage
1 - 2 daysAll prices are indicative UK market ranges based on current UK specialist supplier data.| Repair Tier | Dealer (Parts + Labour) | Specialist (Parts + Labour) | What It Involves | Suitability | Estimated Time |
|---|---|---|---|---|---|
 Valve Cover & PCV Replacement Minor | £1,200-£1,800 | £700-£1,200 | Replace complete valve cover with integrated PCV, new gaskets, breather hoses | Restores crankcase pressure control; 60,000+ mile lifespan | 1 - 2 days |
 Full Replacement - rebuilt/reconditioned engine Best Value | £8,500-£12,000 | £5,500-£8,500 | Supply & fit rebuilt B58 with upgraded valve cover and PCV components, 12-month warranty | Required if oil consumption caused catalytic converter damage | 1 - 2 days |
Vehicle Value Check
Vehicle Value Check
A typical BMW Z4 M40i is worth £30,000-£50,000 depending on age, mileage, and specification. Given the vehicle's premium value, engine replacement is generally viable even at the upper end of the cost range. For higher-mileage examples with other wear issues, evaluate the vehicle's overall condition before committing.
Our Recommendation
Our Recommendation
PCV failure on the B58 is a well-understood issue. Specialist valve cover replacement with an upgraded PCV unit costs under £1,200 and resolves the problem permanently. This is almost always the right first step - a full engine replacement is rarely necessary unless the engine has suffered catastrophic failure or exceeded 100,000 miles with multiple other issues.
Don't Let Engine Failure Write Off Your BMW Z4 M40i
A failed B58 doesn't have to mean the end of the road for your Z4 M40i. Whether you're facing PCV failure, water pump failure, or charge pipe issues, EnginesMarket connects you with trusted UK BMW turbo specialists who supply rebuilt engines with upgraded components specifically designed to address the original failure points. Every engine comes with a minimum 12-month unlimited mileage warranty, nationwide delivery, and supply & fit options across the UK. Compare prices today - and keep one of BMW's most thrilling roadsters on the road without paying the main dealer premium.
Compare rebuilt B58 engine prices for your BMW Z4 M40i
12-Month Minimum
UK Specialists Vetted
Best Price GuidanceImportant Information
Important Information
"All prices are indicative UK market ranges based on historical quote data and repair requests from our network of engine specialists. Dealer pricing is estimated based on published main dealer labour rates and genuine OEM parts pricing. Specialist pricing reflects actual quote data from EnginesMarket's UK network. Actual costs vary depending on damage severity, vehicle condition, variant, and workshop location within the UK. Use our free comparison tool to get tailored quotes for your specific BMW Z4 M40i. Every engine supplied through EnginesMarket carries a minimum 12-month unlimited mileage warranty - always confirm exact terms with your chosen supplier."
BMW Z4 M40i Engine ReplacementFrequently Asked Questions
Question 1How much does a BMW Z4 M40i engine replacement cost in the UK-
A BMW Z4 M40i engine replacement typically costs £3,500-£7,500 supply-only for rebuilt units, or £5,500-£10,500 fitted by a specialist.
- Used B58B30 engines: £2,500-£4,500 supply-only
- Reconditioned units: £4,200-£6,500 supply-only
- Rebuilt units with warranty: £5,500-£8,500 supply-only
- Professional fitting adds £1,000-£2,000 depending on workshop location
- LCI B58B30M2 units command premium pricing: £3,500-£5,500 used
Question 2Is the BMW Z4 M40i B58 engine reliable-
The B58 is widely regarded as one of BMW's most reliable modern turbo engines. However, it has known weaknesses that typically appear between 50,000-100,000 miles.
- PCV diaphragm failure integrated into valve cover - replace with upgraded unit
- Electric water pump failure - replace preventatively at 60k miles
- Charge pipe cracking on track cars - upgrade to aluminium
- Regular oil changes with BMW LL-01 approved oil are essential
- Many owners report 100,000+ miles with no major issues
Question 3What are the signs of PCV failure in a BMW Z4 M40i-
The most common symptoms are a whistling noise from the engine bay, excessive oil consumption (1L per 1,000 miles or more), rough idle, and visible oil leaks around the valve cover.
- Whistling noise that changes with engine RPM
- Oil consumption increasing noticeably
- Blue smoke on start-up
- PCV failure can lead to oil seal failure if left unchecked
- Specialist valve cover replacement costs £700-£1,200
Question 4What are the signs of water pump failure in a BMW Z4 M40i-
The B58's electric water pump can fail suddenly with little warning.
- Overheating within a mile of failure
- Coolant loss without visible external leaks
- Warning lights on the dashboard
- Electric water pump failure is more common than mechanical pump failure on B58 engines
- Proactive replacement at 60k-70k miles is strongly recommended
Question 5Is it worth replacing the engine on a high-mileage BMW Z4 M40i-
For a Z4 M40i worth £30,000-£50,000, a rebuilt B58 at £5,500-£8,500 can make financial sense if the body, interior, and chassis are in good condition.
- Compare replacement cost against vehicle value - replacement is viable up to 70% of car's value
- Low-mileage M40i examples command strong money (£30k-£40k)
- B58 is a robust engine - replacement restores factory performance
- Always factor 12-month warranty into replacement decision
Question 6What's the difference between the Z4 M40i and the Z4 sDrive30i-
The key differences between the Z4 M40i and sDrive30i are significant:
- M40i uses turbocharged B58B30, 340-382hp - performance flagship
- sDrive30i uses naturally aspirated N52B30, 258hp - more economical
- M40i replacement costs significantly more (£5,500-£8,500 vs £2,400-£3,800 for N52)
- M40i offers 0-62mph in 4.5 seconds vs 5.5+ seconds for 30i
- M40i is the choice for performance enthusiasts
Why Choose UsCompare BMW Z4 M40iEngine PricesToday
11,000+ BMW Z4 engines supported through our network, including M40i variants
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Comparing quotes for your BMW Z4 M40i is free, no-obligation, and specific to your exact G29 roadster and its engine code - B58B30, B58B30M1, or B58B30M2. Whether you need a used replacement, a reconditioned unit, or a full rebuilt engine with upgraded components, our network of trusted UK BMW turbo specialists delivers transparent pricing and nationwide coverage. Don't let a failed engine end the life of BMW's most thrilling roadster - compare prices today and get back on the road with confidence.
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