BMW Z4 sDrive35i / 35is2009–20162 Engine Variants

BMW Z4 sDrive35i / 35is Engine Replacement —Compare Prices &
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Name: BMW Z4 sDrive35i / 35is UK Engine Enquiry Data 2025
Creator: BMWEngines.uk

The Z4's twin-turbo straight-six flagship — the N54-powered sDrive35i and the uprated sDrive35is with overboost. Get quotes from trusted UK BMW specialists who understand these complex performance engines, supply & fit available nationwide.

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BMW Z4 sDrive35i / 35is Engines — from £2,500 to £11,000Common codes: N54B30A, N54B30TO

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100% Free
Reconditioned
Rebuilt
Used
Supply & Fit Available
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The sDrive35i / 35is Through Time — Era Map

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

Era Note

306 bhp — HPFP, injectors and wastegate rattle are the main concerns

Era Note

335–340 bhp with overboost — higher stress on turbos and HPFP

Generation	Years	Engine Code	Reliability	Recon Cost (Guide)	Era Note
Z4 E89 (sDrive35i)	2009–2016	N54B30A / N54B30O0		£4,500–£9,500[PLACEHOLDER]	306 bhp — HPFP, injectors and wastegate rattle are the main concerns
Z4 E89 (sDrive35is)	2010–2016	N54B30TO		£5,000–£11,000[PLACEHOLDER]	335–340 bhp with overboost — higher stress on turbos and HPFP

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 Z4 sDrive35i / 35is Engine Replacement Costs

Supply Only£4,500 – £9,500
Fitted (Indie)£6,000 – £11,500
Warranty12–24 months
Best ForMost owners — best cost/warranty balance

Engine Type	Supply Only	Fitted (Indie)	Warranty	Best For
Used Engine	£2,500 – £4,500	£3,500 – £6,500	1–6 months	Budget priority; short-term ownership
Reconditioned Engine	£4,500 – £9,500	£6,000 – £11,500	12–24 months	Most owners — best cost/warranty balance
Rebuilt Engine	£6,000 – £11,000	£7,500 – £13,500	12–24 months	Long-term ownership; 3+ year horizon
Main Dealer New	£10,000 – £16,000	£12,000 – £19,000	24–36 months	Insurance jobs, warranty claims

Figures above reflect current market rates. Rebuilt N54 units for the E89 chassis are available with 12-month unlimited mileage warranty. A typical engine replacement cost in the UK ranges between £3,067 and £6,105 or more, with reconditioned engines typically costing £1,200–£2,200 supply only and total installed costs around £1,800–£2,800 for simpler engines — N54-specific costs are significantly higher due to complexity.

Labour estimate: Fitting a Z4 N54 engine typically takes 14–20 hours at £65–£95/hr (independent). The tight engine bay and complex twin-turbo layout add significant labour time. The 35is DCT transmission and overboost system add further complexity.

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Common Problems With BMW Z4 sDrive35i / 35is Engines

1. High-Pressure Fuel Pump (HPFP) Failure(N54)

Symptoms: Long cranking before starting, rough idle, loss of power, engine warning light, intermittent stalling, backfiring. In certain cases, the driver may experience reduced engine performance in a Safe Mode.
Typical Mileage: 40,000–80,000 miles — premature failures were widespread, leading to multiple recalls.
Repair Cost: £500–£1,500 (HPFP replacement).
Replacement Cost: N/A — repair only; if ignored, the vehicle may fail to start or go into limp mode.
Urgency: Check — book inspection urgently if symptoms appear.

Our recommendation:

The N54's HPFP is its most infamous weak point. BMW faced class-action lawsuits over defective HPFPs. The pump seems to have an abnormally high rate of failure. Symptoms include long-crank engine starting times. BMW issued multiple recalls covering the HPFP on N54-equipped vehicles. Check whether your Z4 has had the recall work completed. Even with updated pumps, failures can still occur. If you experience any starting issues or loss of power, have the HPFP inspected promptly.

1. High-Pressure Fuel Pump (HPFP) Failure(N54)

Symptoms: Long cranking before starting, rough idle, loss of power, engine warning light, intermittent stalling, backfiring. In certain cases, the driver may experience reduced engine performance in a Safe Mode.
Typical Mileage: 40,000–80,000 miles — premature failures were widespread, leading to multiple recalls.
Repair Cost: £500–£1,500 (HPFP replacement).
Replacement Cost: N/A — repair only; if ignored, the vehicle may fail to start or go into limp mode.
Urgency: Check — book inspection urgently if symptoms appear.

Our recommendation:

2. Fuel Injector Failure(N54)

Symptoms: Rough idle, misfires, decreased performance, poor fuel economy, engine warning light, fuel smell in the oil.
Typical Mileage: 50,000–100,000 miles — earlier injectors (Index 10 or lower) are most susceptible.
Repair Cost: £1,200–£2,500 (full set of six Index 12 injectors).
Replacement Cost: N/A — repair only; if ignored, misfires can damage catalytic converters.
Urgency: Check — book inspection urgently if symptoms appear.

Our recommendation:

N54 fuel injectors are piezo-electric injectors that have more in common with diesel injection than regular gas injectors. The main failure on earlier injectors is clogging and foreign debris restricting flow. On early N54 injectors, there's a filter that's known to melt at high temperatures. BMW redesigned these injectors numerous times — updated Index 12 injectors are the current solution. Any injector marked ten or lower in the same cylinder bank will require all the injectors in the bank to be replaced. A full set of Index 12 injectors is a common preventative upgrade on N54 cars.

3. Turbocharger Wastegate Rattle(N54)

Symptoms: Rattling noise from the engine bay, particularly on cold start or deceleration, turbo lag, reduced performance, check engine light.
Typical Mileage: 60,000–100,000 miles — the wastegate bushings wear over time.
Repair Cost: £800–£2,500 (wastegate actuator adjustment or rebuild) / £1,500–£4,000 (turbocharger replacement).
Replacement Cost: N/A — repair only if caught early; if ignored, boost pressure drops and performance suffers.
Urgency: Monitor — book inspection soon if rattling is present.

Our recommendation:

Wastegate rattle is a common complaint on the N54. The wastegate bushings wear, causing rattling and reduced boost control. While not immediately catastrophic, it can lead to reduced performance and eventual turbo failure if ignored. Some specialists offer wastegate actuator repair kits as a cost-effective alternative to full turbo replacement. For the 35is, the higher boost pressure from the overboost function accelerates wastegate wear.

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Z4 sDrive35i / 35is — 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
HPFP failure	Yes	£500 – £1,500	Essential repair — vehicle may be undriveable without it
Injector failure	Yes	£1,200 – £2,500	Replace all six with Index 12 units — coding required
Wastegate rattle	Yes (if caught early)	£800 – £4,000	Adjust or rebuild — cheaper than full turbo replacement
Oil leaks (gaskets)	Yes	£300 – £1,000	Common maintenance — repair when symptoms appear
Carbon build-up	Yes	£400 – £800	Walnut blasting — recommended every 60,000–80,000 miles
Catastrophic engine failure	Usually No	Engine replacement	Full engine replacement required if bottom-end or valvetrain fails

ProblemRepairable? · Typical Cost

HPFP failure

Yes£500 – £1,500

Essential repair — vehicle may be undriveable without it

Injector failure

Yes£1,200 – £2,500

Replace all six with Index 12 units — coding required

Wastegate rattle

Yes (if caught early)£800 – £4,000

Adjust or rebuild — cheaper than full turbo replacement

Oil leaks (gaskets)

Yes£300 – £1,000

Common maintenance — repair when symptoms appear

Carbon build-up

Yes£400 – £800

Walnut blasting — recommended every 60,000–80,000 miles

Catastrophic engine failure

Usually NoEngine replacement

Full engine replacement required if bottom-end or valvetrain fails

Buying This Z4 sDrive35i / 35is? Check These First

Buy if:

HPFP recall completed or recently replaced — the most critical N54 issue
Index 12 injectors fitted — the updated injectors are far more reliable
No wastegate rattle on cold start or deceleration
Carbon cleaning (walnut blasting) performed recently
Full service history with regular oil changes (every 8,000–10,000 miles)

Avoid if:

Long cranking on startup — HPFP failure imminent
Rough idle or misfires — injector failure is likely
Rattling from the turbo area — wastegate rattle
Oil leaks from valve cover or oil filter housing — common but costly to fix
Poor service history — the N54 is unforgiving of neglect

Closing verdict

The Z4 sDrive35i and 35is are among the most exciting roadsters BMW has ever built — the N54 engine is a tuner's dream with forged internals from the factory. However, it comes with a well-earned reputation for reliability issues. The HPFP, injectors, and wastegate are the three biggest concerns. The 35is adds even more stress on these components with its higher boost and overboost function. With the 70% BMW scrap threshold, a £7,000 recon on a £10,000 Z4 is 70% — borderline. On a sub-£8,000 example, think carefully. The N54's tuning potential and the Z4's classic roadster status often justify replacement spend if the rest of the car is in good condition.

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Buying Checklist

Before you buy a used BMW Z4 sDrive35i / 35is (or before you commit to an engine replacement), check these:

1. Cold Start
Listen for long cranking (HPFP failure) or rattling (wastegate rattle)
2. Idle Quality
Any rough idle or misfires? (injector failure)
3. Service History
HPFP recalls completed? Index 12 injectors fitted?
4. Carbon Cleaning
Has walnut blasting been performed? (recommended every 60,000–80,000 miles)
5. Oil Leaks
Check around valve cover and oil filter housing
6. Turbo Check
Any whistling, smoke, or power loss?
7. DCT Check
For 35is, check for smooth gear changes — DCT issues are expensive
8. MOT History
Check for emissions-related failures

Why this matters

A 10-minute check now can save you thousands later. The right Z4 sDrive35i / 35is is a superb long-term car — the wrong one can be expensive fast.

Buying Checklist

Before you buy a used BMW Z4 sDrive35i / 35is (or before you commit to an engine replacement), check these:

1
Cold Start
Listen for long cranking (HPFP failure) or rattling (wastegate rattle)
2
Idle Quality
Any rough idle or misfires? (injector failure)
3
Service History
HPFP recalls completed? Index 12 injectors fitted?
4
Carbon Cleaning
Has walnut blasting been performed? (recommended every 60,000–80,000 miles)
5
Oil Leaks
Check around valve cover and oil filter housing
6
Turbo Check
Any whistling, smoke, or power loss?
7
DCT Check
For 35is, check for smooth gear changes — DCT issues are expensive
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 Z4 sDrive35i / 35is pitfalls.

Engine Codes

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

N54B30A / N54B30O0

Years: 2009–2016
Power: 306 bhp (225 kW)
2025 Enquiries: —(pattern data)
Avg. Recon Cost: £4,500–£9,500[PLACEHOLDER]

Engine Code	Years	Power	2025 Enquiries	Avg. Recon Cost
N54B30A / N54B30O0	2009–2016	306 bhp (225 kW)	—(pattern data)	£4,500–£9,500[PLACEHOLDER]
N54B30TO	2010–2016	335–340 bhp (250 kW)	—(pattern data)	£5,000–£11,000[PLACEHOLDER]

Technical SpecsN54B30TO — sDrive35is

Displacement: 2,979 cc
Cylinders: 6-cylinder inline, 24-valve DOHC
Compression Ratio: 10.2:1
Fuel System: Direct injection
Turbocharger: Twin-turbocharged (parallel)
Displacement: 2,979 cc
Cylinders: 6-cylinder inline, 24-valve DOHC
Compression Ratio: 10.2:1
Fuel System: Direct injection
Turbocharger: Twin-turbocharged with overboost function

Compare Z4 sDrive35i / 35is engine prices for your BMWGet quotes from trusted UK specialists in minutes.

Market Intelligence

Real data from thousands of Z4 sDrive35i / 35is enquiries in 2025.

Most Common FailureHPFP

Premature failures were widespread, leading to multiple recalls

[PATTERN DATA]

Average Enquiry Mileage

70,000

miles

[PATTERN DATA]

Average Replacement Cost

£6,500

reconditioned, supply only

[PLACEHOLDER]

Most Requested Engine Code

N54B30A (sDrive35i

Highest-volume variant)

[PATTERN DATA]

Peak Enquiry Season

Spring/Summer

Convertible owners recommissioning after winter

[PATTERN DATA]

Regional Demand

South East: 22%
London: 18%
South West: 16%
Other Regions: 44%

[PATTERN DATA]

Regional Demand Breakdown

18%London22%South East16%South West44%Other Regions

Frequently Asked Questions

A reconditioned Z4 N54 engine typically costs £4,500–£11,000 supply only depending on the variant. sDrive35i units sit at the lower end (£4,500–£9,500), while sDrive35is units run £5,000–£11,000. Fitting adds £900–£2,000 depending on workshop location. Rebuilt N54 units for the E89 chassis are available with 12-month unlimited mileage warranty. Use our calculator for a figure specific to your car.

The N54 is a legendary engine among enthusiasts — it's one of the most capable and sought-after engines in the marketplace. However, it's not without its faults. Common issues include HPFP failure, fuel injector failure, wastegate rattle, oil leaks, and carbon build-up. The 35is adds more stress with higher boost and an overboost function, which can accelerate wear on these components. With proper maintenance and preventative upgrades (Index 12 injectors, updated HPFP), the N54 can be a reliable and rewarding engine.

HPFP failure (long cranking, rough idle, loss of power), fuel injector failure (rough idle, misfires), turbocharger wastegate rattle (rattling noise, boost loss), oil leaks from valve cover and oil filter housing gaskets, and carbon build-up on intake valves. The HPFP and injectors are the most expensive and common failures.

Apply the 70% BMW scrap threshold: if your Z4 is worth £10,000 and a recon engine is £6,500 (65%), it's borderline. If the vehicle is a tired £8,000 example, the same engine exceeds 70% — get a scrap valuation first. The Z4's classic roadster status and the N54's tuning potential often justify replacement spend if the rest of the car is in good condition.

Listed on the VIN plate and vehicle documentation. The sDrive35i uses the N54B30A or N54B30O0 (306 bhp), while the sDrive35is uses the N54B30TO (335–340 bhp with overboost). The Z4 E89 was produced from 2009 to 2016. Tell us your registration date and we'll confirm it for free.

The HPFP typically requires replacement rather than repair (£500–£1,500). BMW issued multiple recalls covering HPFP failures on N54-equipped vehicles. Check whether your Z4 has had the recall work completed. Even with updated pumps, failures can still occur. If you experience long cranking or loss of power, have the HPFP inspected immediately.

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.

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supply-only or full supply & fit available nationwide, covering everything from HPFP replacement to carbon cleaning to full engine swaps on your E89 Z4.

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BMW Z4 sDrive35i / 35is Engine Replacement —Compare Prices &Get Quotes

The sDrive35i / 35is Through Time — Era Map

BMW Z4 sDrive35i / 35is Engine Replacement Costs

Common Problems With BMW Z4 sDrive35i / 35is Engines

1. High-Pressure Fuel Pump (HPFP) Failure(N54)

2. Fuel Injector Failure(N54)

3. Turbocharger Wastegate Rattle(N54)

1. High-Pressure Fuel Pump (HPFP) Failure(N54)

2. Fuel Injector Failure(N54)

3. Turbocharger Wastegate Rattle(N54)

Weighing Your Options?

Z4 sDrive35i / 35is — Repair, Buy, or Replace?

Can It Be Repaired?

Buying This Z4 sDrive35i / 35is? Check These First

Buying Checklist

Buying Checklist

Engine Codes

Market Intelligence

Regional Demand Breakdown

Frequently Asked Questions

Why UK BMW Z4 sDrive35i / 35is Owners Trust BMWEngines.uk

Trusted Z4 sDrive35i / 35is Engine Suppliers

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