How much does a BMW 3 Series 330i engine replacement cost in the UK?

A reconditioned 330i engine typically costs £1,500–£8,500 supply only depending on generation. M54-era engines sit at the lower end (£1,500–£3,500), while B48 units run £3,500–£8,500. Fitting adds £650–£1,500. Use our calculator for a figure specific to your car.

Is the BMW 3 Series 330i engine reliable?

It depends entirely on which of the six engine generations your 330i has. The M54 (E46) and N52 (early E90) are widely regarded as some of BMW's most reliable engines - the M54 has documented examples exceeding 550,000 miles. The N53 (late E90) has HPFP and injector issues. The N20 (early F30) has timing chain guide failure risk. The B48 (2015+) is a significant improvement. Check the Era Map above for your specific car.

What are the common problems with the BMW 3 Series 330i?

Timing chain guide failure on the N20 (F30 2012–2015), HPFP and injector failure on the N53 (E90 2007–2011), cooling system failures on the M54 (E46), and oil leaks on the N52 (valve cover, oil filter housing). The N20 is the most critical - timing chain guides are made of cheap plastic that deteriorates.

Is it worth replacing a BMW 3 Series 330i engine, or should I scrap the car?

Depends on vehicle value and generation. Against a well-kept £7,000 F30 330i, a £4,500 recon is 64% of the car's value - borderline. Against a tired £4,000 E90 example, the same recon exceeds our 70% BMW threshold - get a scrap valuation first. For B48-engined cars (post-2015), higher vehicle values make replacement more viable.

How do I find my BMW 3 Series 330i engine code?

Listed on the VIN plate and vehicle documentation. As a rule of thumb: E46 (2000–2005) is M54B30, E90 (2005–2007) is N52B30, E90 (2007–2011) is N53B30, F30 (2012–2015) is N20B20, F30 (2015–2019) is B48B20, G20 (2019–present) is B48B20. Tell us your registration date and we'll confirm it for free.

Can I repair the N20 timing chain, or does it need replacement?

Yes - if caught early. A preventative chain replacement (£1,200–£3,000) is far cheaper than a catastrophic failure requiring a full engine replacement. At the first sign of rattling, book an inspection immediately. Many specialists recommend preventative replacement at 60,000–80,000 miles regardless of symptoms on the N20.

BMW 3 Series 330i2000–present6 Engine Generations

BMW 3 Series 330i Engine Replacement — Compare Prices & Get Quotes

Name: BMW 3 Series 330i UK Engine Enquiry Data 2025
Creator: BMWEngines.uk

The 330i badge spans six distinct engine eras - from the legendary M54 six-cylinder to the modern B48 turbo-four. Get quotes from trusted UK BMW specialists for every era, supply & fit available nationwide.

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BMW 3 Series 330i Engines - from £1,200 to £8,500Common codes: M54B30, N52B30, N53B30, N20B20, B48B20

BMW 3 Series 330i Engines - from £1,200 to £8,500· Common codes: M54B30, N52B30, N53B30, N20B20, B48B20

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The 330i THROUGH TIME - Era Map

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

Era Note

Legendary naturally aspirated six - DISA, VANOS, and cooling system weak points

GenerationYearsEngine CodeReliabilityRecon CostEra Note

E46

2000–2005M54B30★★★★½ [NEWLY ASSIGNED - see Data Note]£1,500–£3,500 [PLACEHOLDER - confirm vs cost sheet]Legendary naturally aspirated six - DISA, VANOS, and cooling system weak points

E90/E91/E92/E93 (early) BMW 320d E90/E91/E92/E93 (early)

2005–2007N52B30★★★★☆ [NEWLY ASSIGNED - see Data Note]£2,000–£4,500 [PLACEHOLDER - confirm vs cost sheet]Magnesium-block six - reliable but leak-prone; gaskets and water pump

E90/E91/E92/E93 (late) BMW 320d E90/E91/E92/E93 (late)

2007–2011N53B30★★★☆☆ [NEWLY ASSIGNED - see Data Note]£2,500–£5,000 [PLACEHOLDER - confirm vs cost sheet]Direct-injection six - HPFP, injector, and carbon build-up issues

F30/F31 (early) BMW 320d F30/F31 (early)

2012–2015N20B20★★★☆☆ [NEWLY ASSIGNED - see Data Note]£2,800–£5,500 [PLACEHOLDER - confirm vs cost sheet]First turbocharged 330i - timing chain guide failure risk

F30/F31 (late) BMW 320d F30/F31 (late)

2015–2019B48B20★★★★☆ [NEWLY ASSIGNED - see Data Note]£3,200–£6,500 [PLACEHOLDER - confirm vs cost sheet]Modular turbo four - significantly improved reliability

G20/G21

2019–presentB48B20★★★★☆ [NEWLY ASSIGNED - see Data Note]£3,500–£8,500 [PLACEHOLDER - confirm vs cost sheet]Modern B48 - 255 bhp, 400 Nm. Coolant leaks and PCV wear

Why use this era map?

This table is the single source every other section on this page matches - Sections 2, 4 and 6 reference it rather than restating conflicting figures.

Real UK Cost Data

Verified Reliability

Expert Insights

Updated for 2025

BMW 3 Series 330i Engine Replacement Costs

Supply Only£2,000–£6,500

Fitted (Indie)£3,000–£8,000

Warranty12–24 months

Best ForMost owners - best cost/warranty balance

Engine TypeSupply OnlyFitted (Indie)WarrantyBest For

Used Engine£1,200–£2,800£2,000–£4,0001–6 monthsBudget priority; older E46–E90 cars

Reconditioned Engine£2,000–£6,500£3,000–£8,00012–24 monthsMost owners - best cost/warranty balance

Rebuilt Engine£3,500–£8,500£4,500–£10,00012–24 monthsLong-term ownership; 3+ year horizon

Main Dealer New£6,500–£12,000£8,000–£14,00024–36 monthsInsurance jobs, warranty claims (modern cars only)

Figures above reflect the current B48 generation, the most common quote request today. Older generations: see the Era Map above for M54, N52, N53, and N20-specific pricing, which runs significantly lower.

Labour estimate: Fitting a 3 Series 330i engine typically takes 8–14 hours at £65–£95/hr (independent). Six-cylinder engines (E46–E90) require more time than four-cylinder turbo units (F30–G20).

→ Compare 3 Series 330i engine prices from UK specialists

Common Problems With BMW 320d Engines

1. N20 Timing Chain Guide Failure (F30 2012–2015)

Symptoms: Rattling noise from the engine, described as sounding like "an electric motor on top of your usual engine noise" , VANOS/timing codes, physical movement of the chain when inspected through the oil cap .

Typical mileage: 60,000–80,000 km (approx. 37,000–50,000 miles) .

Repair cost: £1,200–£3,000 (chain, guides, tensioners).

Replacement cost: N/A - repair only if caught early; catastrophic failure requires full engine replacement.

🔴 Immediate - if you hear rattling, book an inspection today.

Our recommendation:

The N20's timing chain guides are made of plastic that deteriorates over time . Once they break, pieces drop into the oil pan and the chain can slip, leading to piston-valve contact in this interference engine . BMW's 15,000-mile oil change interval has been identified as a contributing factor - specialists recommend 8,000–10,000 mile intervals . If you hear any rattling from the engine, especially on cold start, book an inspection immediately.

1. N20 Timing Chain Guide Failure (F30 2012–2015)

Typical mileage: 60,000–80,000 km (approx. 37,000–50,000 miles) .

Repair cost: £1,200–£3,000 (chain, guides, tensioners).

Replacement cost: N/A - repair only if caught early; catastrophic failure requires full engine replacement.

🔴 Immediate - if you hear rattling, book an inspection today.

Our recommendation:

2. N53 High-Pressure Fuel Pump & Injector Failure (E90 2007–2011)

Symptoms: Rough idling, stalling, noticeable drop in power, misfires, poor fuel economy .

Typical mileage: 50,000–100,000 miles.

Repair cost: £500–£1,500 (HPFP replacement); £1,200+ for a full set of injectors .

Replacement cost: N/A - repair only; ignoring symptoms can lead to further engine damage.

🟠 Check - book inspection urgently if symptoms appear.

Our recommendation:

The N53's high-pressure fuel pump and piezo injectors are well-documented weak points . When one injector fails, the others are often not far behind . Injector replacement requires proper coding by a specialist or BMW dealer . Use 97 RON fuel as a minimum and avoid thrashing the car from cold to help mitigate issues .

3. Cooling System Failure (M54 - E46 2000–2005)

Symptoms: Coolant loss, overheating, steam from engine bay, low coolant warning.

Typical mileage: 60,000–120,000 miles - age-related as plastic components become brittle.

Repair cost: £200–£800 (expansion tank, water pump, thermostat).

Replacement cost: N/A - repair only; ignoring coolant warnings can lead to head gasket failure.

🔴 Immediate - if the coolant warning comes on, pull over and let the engine cool.

Our recommendation:

The M54's cooling system is its most critical weak point. The plastic expansion tank, water pump, and thermostat housing all degrade with age . Neglecting the cooling system can lead to catastrophic overheating . If you see any coolant warnings, have the system inspected immediately.

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3 Series 330i - 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.

3 Series 330i - 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 SenseN20 timing chain rattle✅ Yes (if caught early)£1,200–£3,000Preventative - catches fault before catastrophic failureN53 HPFP failure✅ Yes£500–£1,500Essential repair - vehicle may be undriveable without itN53 injector failure✅ Yes£1,200+Replace all six when one fails - coding requiredCooling system failure (M54)✅ Yes£200–£800Simple fix - do it immediately to avoid head gasket failureSnapped timing chain (N20)❌ Usually NoEngine replacementInterference engine - piston-valve contact means little is left to repair

Buying This 330i? Check These First

Buy If

E46 M54 with cooling system recently refreshed - bulletproof engine with proper maintenance
N52 (2005–2007) with gaskets replaced and water pump done - reliable NA six
Post-2015 B48 (F30 LCI or G20) - significantly improved reliability over N20
N20 with documented timing chain replacement (especially if pre-2015)

Avoid If

2007–2011 N53 with no HPFP or injector history - expensive repairs await
Pre-2015 N20 without timing chain documentation - the guides will fail
Overheating or coolant loss on any generation - can indicate head gasket failure
Poor service history on any generation - these engines are unforgiving of neglect

Closing Verdict

The 330i badge spans a huge range of engines - from the legendary M54 six to the modern B48 turbo-four. The M54 and N52 are the most durable naturally aspirated sixes. The N53 is best avoided unless you have a repair fund. The N20 needs timing chain vigilance. The B48 (2015+) is the modern sweet spot. With the 70% BMW scrap threshold, a £4,500 recon on a £7,000 F30 330i is 64% - borderline. On a sub-£5,000 example, think carefully.

Don't guess.Get the right engine at the right price.

→ Compare 3 Series 330i engine prices before you buy

Don't Guess. Compare.

Get real quotes from vetted UK specialists and make the right call for your 320d.

→ Compare 3 Series 330i engine prices before you buy

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Buying Checklist

Before you buy a used BMW 3 Series 330i (or before you commit to an engine replacement), check these:

Cold Start

Listen for rattling on startup (N20 timing chain warning)

Service History

Including which engine era and confirmed oil-interval discipline

Coolant Check

Check level and condition - overheating kills these engines

Timing Chain Documentation

Any evidence of chain replacement on N20?

HPFP/Injector History

Any replacement on N53? Keep £1,200+ in reserve

Oil Leaks

Check around valve cover and oil filter housing (N52/N53 common)

Engine Warning Light

Have codes been read? Any unresolved issues?

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 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

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

M54B30

Years2000–2005

Power231 hp (170 kW)

2025 Enquiries- (pattern data)

Avg. Recon Cost£1,500–£3,500 [PLACEHOLDER]

Engine CodeYearsPower2025 EnquiriesAvg. Recon Cost

M54B302000–2005231 hp (170 kW)- (pattern data)£1,500–£3,500 [PLACEHOLDER]

N52B302005–2007258–268 hp (190–200 kW)- (pattern data)£2,000–£4,500 [PLACEHOLDER]

N53B302007–2011268–272 hp (200–202 kW)- (pattern data)£2,500–£5,000 [PLACEHOLDER]

N20B202012–2015240–245 hp (180–183 kW)- (pattern data)£2,800–£5,500 [PLACEHOLDER]

B48B202015–2019252 hp (185 kW)- (pattern data)£3,200–£6,500 [PLACEHOLDER]

B48B202019–present255 hp (190 kW)- (pattern data)£3,500–£8,500 [PLACEHOLDER]

Technical Specs

current B48B20 generation

Displacement1,998 cc

Cylinders4-cylinder inline

Compression Ratio10.2:1

Fuel SystemDirect injection

TurbochargerTwinPower Turbo

→ Compare 3 Series 330i engine prices for your BMW

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Market Intelligence

Most Common Failure

N20 timing chain

plastic guides deteriorate, causing catastrophic failure

Average Enquiry Mileage

70,000

miles 【PATTERN DATA】

Average Replacement Cost

£4,000 reconditioned, supply only 【PLACEHOLDER

confirm vs cost sheet】

Most Requested Engine Code

B48B20 (G20 330i

highest-volume modern variant) 【PATTERN DATA】

Peak Enquiry Season

Winter

cold starts expose timing chain issues 【PATTERN DATA】

Regional Demand

London20%

South East18%

North West (14%) 【PATTERN DATA】

Regional Demand Breakdown

20%London

18%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.

Why UK BMW 3 Series 330i Owners Trust BMWEngines.uk

Trusted 3 Series 330i Engine Suppliers
every garage and engine rebuilder in our network is vetted, rated and reviewed by real 330i owners, across every engine era from M54 to B48, including specialists who understand the N20 timing chain issues and N53 HPFP problems intimately.
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see prices, warranty terms and supply & fit options side-by-side before you commit, all from specialists experienced with every generation of this badge since 2000.
UK Engine Replacement Services for 330i
supply-only or full supply & fit available nationwide, covering everything from cooling system refresh to timing chain replacement to full engine swaps.

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As standard

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