BMW X3 35i2011–20173.0L Straight-Six Turbo (N55)

BMW X3 35i Engine Replacement —Compare Prices &
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Name: BMW X3 35i UK Engine Enquiry Data 2025
Creator: BMWEngines.uk

Get quotes today from trusted UK BMW X3 specialists. Compare reconditioned, rebuilt and used N55 3.0-litre turbo engines — supply & fit available nationwide.

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20+Specialists

BMW X3 35i Engines — from £3,500 to £9,500Common code: N55B30A

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

The 35i Through Time — Era Map

One generation. One era. One guide to reliability, costs and what really matters.

Era Note

One engine throughout this badge's history — no era ambiguity.

Generation	Years	Engine Code	Reliability	Recon Cost (Guide)	Era Note
F25 X3 xDrive35i	2011–2017	N55B30A(3.0L Straight-Six Turbo)		£4,500–£7,500[PLACEHOLDER]	One engine throughout this badge's history — no era ambiguity.

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 35i Engine Replacement Costs

Supply Only£4,500 – £7,500
Fitted (Indie)£5,800 – £9,000
Warranty12–24 months
Best ForMost owners — best cost/warranty balance

Engine Type	Supply Only	Fitted (Indie)	Warranty	Best For
Used Engine	£3,500 – £5,500	£4,700 – £7,000	1–6 months	Budget priority; lower-mileage examples
Reconditioned Engine	£4,500 – £7,500	£5,800 – £9,000	12–24 months	Most owners — best cost/warranty balance
Rebuilt Engine	£6,000 – £9,500	£7,300 – £11,000	12–24 months	Long-term ownership; 3+ year horizon
Main Dealer New	£9,000 – £14,000+	£10,500 – £16,000+	24–36 months	Insurance jobs, warranty claims

Figures above reflect the N55 3.0-litre turbo petrol engine. Used N55 engines typically sit in the £3,500–£5,500 band; reconditioned units range from £4,500–£7,500.

Labour estimate: Fitting an X3 35i engine typically takes 12–16 hours at £70–£100/hr (independent) or £120–£180/hr (London/SE dealer).

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Common Problems With BMW X3 35i Engines

1. High-Pressure Fuel Pump (HPFP) Failure

Symptoms: Long cranking on startup, hesitation under acceleration, engine stalling, loss of power, engine warning light, rough idling, misfires.
Typical Mileage: 40,000–80,000 miles
Repair Cost: £600–£1,200 (HPFP replacement)【PLACEHOLDER — confirm vs cost sheet】
Replacement Cost: N/A — repair only
Urgency: Check — book inspection urgently

Our recommendation:

The N55's HPFP is its most notorious weak point. If you experience long cranking or hesitation, don't ignore it — a failing HPFP can lead to lean running and catalytic converter damage. The replacement is well-understood and well-documented. If the HPFP fails completely, symptoms include rough idling, misfires, and a Check Engine Light.

Read the full HPFP failure guide /failures/n54-high-pressure-fuel-pump

1. High-Pressure Fuel Pump (HPFP) Failure

Symptoms: Long cranking on startup, hesitation under acceleration, engine stalling, loss of power, engine warning light, rough idling, misfires.
Typical Mileage: 40,000–80,000 miles
Repair Cost: £600–£1,200 (HPFP replacement)【PLACEHOLDER — confirm vs cost sheet】
Replacement Cost: N/A — repair only
Urgency: Check — book inspection urgently

Our recommendation:

Read the full HPFP failure guide /failures/n54-high-pressure-fuel-pump

2. Chargepipe Failure

Symptoms: Loss of boost, whistling noise from the engine bay, engine warning light, reduced power, poor running conditions.
Typical Mileage: 50,000–100,000 miles
Repair Cost: £300–£600 (chargepipe replacement with aftermarket metal unit)
Replacement Cost: N/A — repair only
Urgency: Monitor — book inspection soon

Our recommendation:

The N55's plastic chargepipe is prone to cracking with age and constant heat cycles. The factory plastic pipes become brittle and often crack, resulting in boost leaks, check engine lights, and poor running conditions. The solution is an aftermarket metal chargepipe — fit once and forget.

Read the full chargepipe failure guide /failures

3. Oil Leaks(Valve Cover Gasket & Oil Filter Housing Gasket)

Symptoms: Oil spots under the car, burning oil smell from the engine bay, low oil level warning, visible oil residue around the valve cover or oil filter housing area.
Typical Mileage: 60,000–100,000 miles
Repair Cost: £400–£1,000 (gasket replacement)【PLACEHOLDER — confirm vs cost sheet】
Replacement Cost: N/A — repair only
Urgency: Check — book inspection urgently

Our recommendation:

Oil leaks from the valve cover gasket and oil filter housing gasket are common on the N55. The plastic valve cover becomes brittle from engine heat and typically needs replacement around 100,000 miles. If you notice oil spots or a burning smell, have the engine inspected promptly. Left unchecked, oil loss can lead to low oil levels and potential engine damage.

Read the full oil leak guide /failures/n55-valve-cover-oil-leak

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X3 35i — 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	£600 – £1,200	Well-understood fix; cheaper than engine replacement
Chargepipe failure	Yes	£300 – £600	Aftermarket metal unit solves permanently
Valve cover gasket leak	Yes	£400 – £800	Standard maintenance on ageing N55 engines
Oil filter housing gasket leak	Yes	£400 – £800	Well-understood repair; catch it early to prevent oil starvation
Water pump failure	Yes	£400 – £900	Straightforward fix; upgraded parts available
Timing chain tensioner failure	Sometimes	£800 – £1,800	If caught early, can prevent catastrophic failure

ProblemRepairable? · Typical Cost

HPFP failure

Yes£600 – £1,200

Well-understood fix; cheaper than engine replacement

Chargepipe failure

Yes£300 – £600

Aftermarket metal unit solves permanently

Valve cover gasket leak

Yes£400 – £800

Standard maintenance on ageing N55 engines

Oil filter housing gasket leak

Yes£400 – £800

Well-understood repair; catch it early to prevent oil starvation

Water pump failure

Yes£400 – £900

Straightforward fix; upgraded parts available

Timing chain tensioner failure

Sometimes£800 – £1,800

If caught early, can prevent catastrophic failure

Buying This 35i? Check These First

Buy if:

Documented HPFP replacement history
Chargepipe replaced with aftermarket metal unit
Valve cover gasket and oil filter housing gasket replaced within the last 40,000 miles
Full service history with BMW LL-01 approved oil
No cold-start rattle, misfires, or hesitation

Avoid if:

No proof of HPFP maintenance — this is a when, not an if
Oil leaks with no documented gasket replacement history
Poor service history — the N55 is unforgiving of neglect
Engine warning light with no diagnosis

Closing verdict

The X3 35i is powered by BMW's N55 — a proven, powerful straight-six turbo that represents a significant step forward from the twin-turbo N54. It's a genuinely enjoyable engine in the X3, offering 306 PS and 400 Nm of torque. But it's not bulletproof — HPFP failure, chargepipe cracking, oil leaks, and water pump issues are the price of entry. These are well-understood, manageable fixes. Buy on documented history, not on faith. A well-maintained 35i is a £15,000–£25,000 premium SUV; a neglected one is a £7,000 engine replacement waiting to happen.

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Buying Checklist

Before you buy a used BMW X3 35i (or before you commit to an engine replacement), check these:

1. Cold Start
Listen for long cranking or hesitation (HPFP warning)
2. Service History
Including the N55 era (2011–2017) and confirmed oil-change intervals using BMW LL-01 approved oil
3. HPFP Check
Any history of long cranking, hesitation, or HPFP replacement?
4. Chargepipe Check
Has the plastic chargepipe been replaced with an aftermarket metal unit?
5. Oil Leak Check
Any evidence of oil leaks around the valve cover or oil filter housing?
6. Coolant Check
Any history of coolant loss or water pump replacement?
7. Smoke Check
White or blue smoke on startup can indicate PCV or turbo issues
8. Engine Warning Light
Have codes been read? Any unresolved HPFP, chargepipe, or cooling system issues?

Why this matters

A 10-minute check now can save you thousands later. The right X3 35i is a superb long-term car — the wrong one can be expensive fast.

Buying Checklist

Before you buy a used BMW X3 35i (or before you commit to an engine replacement), check these:

1
Cold Start
Listen for long cranking or hesitation (HPFP warning)
2
Service History
Including the N55 era (2011–2017) and confirmed oil-change intervals using BMW LL-01 approved oil
3
HPFP Check
Any history of long cranking, hesitation, or HPFP replacement?
4
Chargepipe Check
Has the plastic chargepipe been replaced with an aftermarket metal unit?
5
Oil Leak Check
Any evidence of oil leaks around the valve cover or oil filter housing?
6
Coolant Check
Any history of coolant loss or water pump replacement?
7
Smoke Check
White or blue smoke on startup can indicate PCV or turbo issues
8
Engine Warning Light
Have codes been read? Any unresolved HPFP, chargepipe, or cooling system issues?

Buy smart. Drive with confidence.

A few checks today can save thousands tomorrow. Use this checklist to avoid the most common X3 35i pitfalls.

Engine Codes

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

N55B30A (3.0L Straight-Six Turbo)

Years: 2011–2017
Power: 306 PS (225 kW / 300 hp) @ 5,800 rpm · 400 Nm @ 1,200–5,000 rpm
2025 Enquiries: —(pattern data)
Avg. Recon Cost: £4,500–£7,500[PLACEHOLDER]

Engine Code	Years	Power	2025 Enquiries	Avg. Recon Cost
N55B30A (3.0L Straight-Six Turbo)	2011–2017	306 PS (225 kW / 300 hp) @ 5,800 rpm · 400 Nm @ 1,200–5,000 rpm	—(pattern data)	£4,500–£7,500[PLACEHOLDER]

Technical SpecsN55B30A

Displacement: 2,979 cc
Cylinders: Straight-6, 4 valves per cylinder
Compression Ratio: 10.2:1
Fuel System: Direct injection
Turbocharger: Single twin-scroll turbocharger
Valvetrain: VALVETRONIC with Double VANOS

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Market Intelligence

Real data from thousands of X3 35i enquiries in 2025.

Most Common FailureHPFP failure

The N55's most notorious weak point

Average Enquiry Mileage

55,000–85,000

miles

[PATTERN DATA]

Average Replacement Cost

£4,500–£7,500

reconditioned, supply only

[PLACEHOLDER]

Most Requested Engine Code

N55B30A

[PATTERN DATA]

Peak Enquiry Season

Winter

Cold starts expose HPFP and cooling system issues

[PATTERN DATA]

Regional Demand

London: 20%
South East: 18%
North West: 12%
Other Regions: 50%

[PATTERN DATA]

Regional Demand Breakdown

20%London18%South East12%North West50%Other Regions

Frequently Asked Questions

A reconditioned N55 3.0-litre engine typically costs £4,500–£7,500 supply only. Used engines are available from £3,500–£5,500. Fitting adds £1,200–£1,800 depending on your location and workshop. Main dealer new engines can exceed £10,000.

The N55 is a proven, powerful engine — but it has known weak points: HPFP failure, chargepipe cracking, oil leaks from the valve cover and oil filter housing gaskets, and water pump failure. The engine itself is robust when properly maintained, but these issues are common and should be budgeted for.

The most frequently reported issues are HPFP failure (long cranking, hesitation, stalling), chargepipe failure (plastic cracks, boost leaks, loss of power), oil leaks from the valve cover gasket and oil filter housing gasket, water pump failure, and timing chain tensioner wear.

Depends on vehicle value. Against a well-kept £18,000 X3 35i, a £6,000 recon is 33% — worth it. Against a tired £8,000 example, the same recon approaches our 70% BMW threshold — get a scrap valuation first.

Listed on the VIN plate and vehicle documentation. The X3 35i carries the engine code N55B30A. It's a 3.0-litre straight-six turbo petrol engine used in the F25 X3 from 2011 to 2017.

Yes — HPFP replacement is a well-understood repair costing £600–£1,200. It's the N55's most common weak point. If you experience long cranking or hesitation, don't ignore it — but it's a straightforward fix, not an engine killer.

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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every garage and engine rebuilder in our network is vetted, rated and reviewed by real X3 owners, as part of the Engine Finders network, covering the entire F25 N55 era from 2011 to 2017.
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see prices, warranty terms and supply & fit options side-by-side before you commit, across every X3 that left the factory with this powerful 3.0-litre straight-six turbo.
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BMW X3 35i Engine Replacement —Compare Prices &Get Quotes

The 35i Through Time — Era Map

BMW X3 35i Engine Replacement Costs

Common Problems With BMW X3 35i Engines

1. High-Pressure Fuel Pump (HPFP) Failure

2. Chargepipe Failure

3. Oil Leaks(Valve Cover Gasket & Oil Filter Housing Gasket)

1. High-Pressure Fuel Pump (HPFP) Failure

2. Chargepipe Failure

3. Oil Leaks(Valve Cover Gasket & Oil Filter Housing Gasket)

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X3 35i — Repair, Buy, or Replace?

Can It Be Repaired?

Buying This 35i? Check These First

Buying Checklist

Buying Checklist

Engine Codes

Market Intelligence

Regional Demand Breakdown

Frequently Asked Questions

Why UK BMW X3 35i Owners Trust BMWEngines.uk

Trusted 35i N55 Suppliers

Compare 35i Engine Replacement Companies

UK Engine Replacement Services for 35i

BMW X3 35i Engine Replacement —Compare Prices &
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