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BMW 3 Series 320i Engine Replacement -Compare Prices & Get Quotes

Get quotes today from trusted UK BMW 3 Series 320i engine specialists. Compare prices on reconditioned, rebuilt and used engines for your 3 Series 320i - supply & fit available nationwide.

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BMW 3 Series 320i engine replacement - N46B20 N43B20 N20B20 B48B20 rebuilt reconditioned UK
BMW 3 Series 320i Engine - from £1,495 to £3,495

-> Rebuilt units from £1,495 · Engine codes: N46B20, N43B20, N20B20, B48B20

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● 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|● 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|
How It Works

3 Simple Stepsto Finding the Best BMW 3 Series 320i Replacement Engine

Live UK Engine Market Data for BMW 3 Series 320i Owners

Most replacements completed within 3-5 days.

12-Month Warranty
Supply & Fit Available
Nationwide Delivery
Trusted UK Suppliers

Variant History

BMW 3 Series 320i Engine History & Production Timeline

The BMW 3 Series 320i has evolved through three distinct generations since 2005, transitioning from naturally aspirated inline-four engines to high-efficiency turbocharged units. Initially launched with the N46 and N43 petrol engines in the E90 chassis, the variant shifted to the N20 turbocharged engine in the F30 generation before adopting the current B48 powertrain in the G20. This progression reflects BMW’s strategic move toward downsized, forced-induction engines that meet stringent Euro 6 emissions standards while maintaining performance. The current G20 generation remains in production, offering the refined B48 engine with improved thermal management and reliability over its predecessors.

Variant History & Key Milestones

2005 - N46B20 introduced with 150 bhp / 200 Nm, marking the entry-level petrol option for the E90 3 Series with Valvetronic technology.

2007 - N43B20 replaced N46 in select markets, offering 170 bhp / 210 Nm with direct injection, though later plagued by high-pressure fuel pump issues.

2012 - N20B20 introduced in the F30 generation, delivering 184 bhp / 270 Nm, marking the shift to turbocharging for the 320i badge.

2015 - B48B20 replaced N20 in the F30 LCI (Life Cycle Impulse), maintaining 184 bhp but increasing torque to 290 Nm (manual) / 270 Nm (auto) and improving reliability.

2019 - G20 generation launched with updated B48B20, producing 184 bhp / 300 Nm, featuring enhanced cooling systems and mild-hybrid integration in later models.

Present - Still in production, with the G20 320i continuing as a core model in the UK lineup until the expected G50 launch in late 2026.

Compatible Engines

BMW 3 Series 320i Engine Codes - Specs, Failures & Replacement Costs

N46B20

2.0L Petrol

Used

£800 - £1,200

Reconditioned

£1,800 - £2,400

Rebuilt

£2,500 - £3,200

Common Failure

Timing chain guide wear and tensioner failure documented across multiple UK owner forums (60k-100k miles), often leading to catastrophic engine damage if ignored.

-> Compare N46B20 BMW 3 Series 320i engine replacement prices

Power

150 bhp / 152 PS

Torque

200 Nm / 148 lb-ft

Years Fitted

2005-2007

Compatible Trims

E90 (2005-2007): SE, Sport, M Sport

All N46B20 engines supplied through our network include upgraded failure-point components and minimum 12-month unlimited mileage warranty.

N43B20

2.0L Petrol

Used

£900 - £1,400

Reconditioned

£2,000 - £2,600

Rebuilt

£2,800 - £3,500

Common Failure

High-pressure fuel pump (HPFP) failure and injector issues widely reported by UK specialists and owners, causing rough running and starting difficulties.

-> Compare N43B20 BMW 3 Series 320i engine replacement prices

Power

170 bhp / 172 PS

Torque

210 Nm / 155 lb-ft

Years Fitted

2007-2011

Compatible Trims

E90/E91/E92/E93 (2007-2011): SE, Sport, M Sport, Exclusive Edition

All N43B20 engines supplied through our network include upgraded failure-point components and minimum 12-month unlimited mileage warranty.

N20B20

2.0L Petrol

Used

£1,200 - £1,800

Reconditioned

£2,200 - £2,900

Rebuilt

£3,000 - £3,800

Common Failure

Timing chain guide wear and tensioner failure documented across multiple UK owner forums (60k-100k miles), with plastic guides prone to breaking and causing chain jump.

-> Compare N20B20 BMW 3 Series 320i engine replacement prices

Power

184 bhp / 181 PS

Torque

270 Nm / 199 lb-ft

Years Fitted

2012-2015

Compatible Trims

F30/F31 (2012-2015): SE, Sport, M Sport, Modern, Luxury

All N20B20 engines supplied through our network include upgraded failure-point components and minimum 12-month unlimited mileage warranty.

B48B20

2.0L Petrol

Used

£1,800 - £2,500

Reconditioned

£2,800 - £3,500

Rebuilt

£3,500 - £4,500

Common Failure

Coolant system leaks from plastic vent lines and thermostat housing cracking cited by UK specialists and forum users, particularly in pre-2018 units.

-> Compare B48B20 BMW 3 Series 320i engine replacement prices

Power

184 bhp / 181 PS

Torque

300 Nm / 221 lb-ft

Years Fitted

2015-Present

Compatible Trims

F30/F31 LCI (2015-2019): SE, Sport, M Sport, Shadow Edition · G20/G21 (2019-Present): SE, Sport, M Sport, M Sport Pro

All B48B20 engines supplied through our network include upgraded failure-point components and minimum 12-month unlimited mileage warranty.

Can't find your engine code? Enter your registration number above - we'll instantly identify the exact unit fitted to your BMW 3 Series 320i and provide live quotes from UK specialists.

Common Problems

BMW 3 Series 320i Engine Problems - What It Costs to Fix & When Replacement Makes Sense

The BMW 3 Series 320i petrol variants, predominantly fitted with N20-B20B (2012-2018) and B48-B20A (2015-2024) turbocharged four-cylinder engines, offer strong performance but face specific reliability challenges documented across UK owner forums and specialist workshops. Every rebuilt BMW 3 Series 320i engine supplied through EngineMarket includes upgraded failure-point components and a minimum 12-month unlimited mileage warranty. Use this guide to compare repair tiers and get instant quotes from certified UK specialists.

Failure Analysis

N20 Timing Chain and Guide Failure

Why BMW 3 Series 320i N20-B20B Engines Fail

-> Compare rebuilt N20-B20B engine prices for your BMW 3 Series 320i

Affected Models

BMW 3 Series 320i SE, Sport, M Sport, EfficientDynamics (2012-2018, N20-B20B)

Typical Failure Mileage

60,000-95,000 miles

Root Cause

The N20 engine's plastic timing chain guides degrade prematurely due to heat cycling and oil quality sensitivity, causing chain slack, rattling on cold start, and potential catastrophic interference damage if the chain skips teeth. This pattern is corroborated across PistonHeads UK forum threads and explicitly listed by UK specialists such as Apexx Engines as a known rebuild trigger apexxengines.co.uk f30.bimmerpost.com www.pistonheads.com

Repair Cost Guide

UK repair routes at a glance

Minor Repair - Early guide inspection/replacement

Dealer

£800-£1,200 (estimated based on standard UK dealer rates)

Specialist

£500-£800

Removal of valve cover, inspection of timing chain tensioner and upper guide, replacement of plastic guide with upgraded metal-reinforced unit

Preventative fix; extends life by 30k-50k miles if caught before chain stretch

Major Repair - Full timing chain kit replacement

Dealer

£1,500-£2,200 (estimated based on standard UK dealer rates)

Specialist

£900-£1,400

Complete timing chain kit (chain, tensioner, guides, sprockets), oil pump chain inspection, fresh synthetic oil and filter

Restores factory timing integrity; suitable if engine still runs without misfire codes

Full Replacement - Rebuilt N20-B20B Engine

Best Value

Dealer

£4,500-£7,000 (estimated based on standard UK dealer rates)

Specialist

£2,300-£3,800

Complete stripped block rebuild with upgraded metal timing chain guides, new tensioner, crankshaft bearings, bench-tested, ECU-matched, 12-month warranty. Workshop-fitted.

Permanent solution when chain has skipped teeth, caused valve/piston contact, or engine has seized

Our Recommendation

If your BMW 3 Series 320i N20-B20B exhibits cold-start rattling before 70k miles, we recommend immediate specialist diagnosis - preventative guide replacement is far more cost-effective than post-failure rebuild. Once interference damage has occurred, full engine replacement with upgraded components is the only reliable long-term solution.

Don't Let Engine Failure Write Off Your BMW 3 Series 320i

Timing chain guide wear and persistent oil leaks represent the two most frequently documented failure patterns on BMW 3 Series 320i petrol engines across UK owner communities. EngineMarket connects you directly with certified UK BMW 3 Series 320i specialists who supply rebuilt units featuring upgraded failure-point components, nationwide delivery, vehicle collection and drop-off recovery services, and minimum 12-month unlimited mileage warranty. Compare live quotes today to get your 320i back on the road without paying main dealer premiums.

Compare BMW 3 Series 320i N20-B20B Engine Replacement Prices Now ->
DISCLAIMER:

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 EngineMarket'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 3 Series 320i and engine code. Every engine supplied through EngineMarket carries a minimum 12-month unlimited mileage warranty - always confirm exact terms with your chosen supplier.

FAQs

BMW 3 Series 320i Engine ReplacementFrequently Asked Questions

Everything BMW 3 Series 320i owners usually ask before choosing a rebuilt, reconditioned or used replacement engine.

Question 1

How much does a BMW 3 Series 320i engine replacement cost in the UK?

A rebuilt BMW 3 Series 320i engine typically costs £2,300-£3,800 supplied and fitted by a specialist, significantly less than main dealer quotes which can exceed £6,000. Prices vary by engine code (N20-B20B or B48-B20A), damage severity, and workshop location.

Key points

  • • Specialist quotes average £2,300-£3,800 for supply and fit of rebuilt unit
  • • Main dealer replacements often exceed £6,000 due to higher labour rates
  • • Full price includes upgraded components addressing original failure pattern
  • • 12-month unlimited mileage warranty standard on EngineMarket network units
  • • Free comparison tool delivers tailored quotes within minutes
  • • Get instant BMW 3 Series 320i engine replacement quotes now
-> Get instant BMW 3 Series 320i engine replacement quotes now

Question 2

Should I choose used, reconditioned, or rebuilt for my BMW 3 Series 320i engine?

Rebuilt BMW 3 Series 320i engines offer the best balance of reliability and value, with upgraded failure-point components and warranty protection that used or basic reconditioned units cannot match.

Key points

  • • Used engines carry unknown history and minimal warranty coverage
  • • Reconditioned units refresh wear items but may retain original weak components
  • • Rebuilt engines include upgraded parts targeting known failure patterns
  • • All EngineMarket rebuilt units carry 12-month unlimited mileage warranty
Important

Never fit a used engine without compression and leak-down testing - hidden damage can cause repeat failure within months.

-> Compare rebuilt vs reconditioned BMW 3 Series 320i engine options today

Question 3

Can I drive my BMW 3 Series 320i if I hear a timing chain rattle?

No - a rattling timing chain on your BMW 3 Series 320i N20-B20B engine signals imminent failure risk; continue driving may cause catastrophic valve/piston damage requiring full engine replacement.

Key points

  • • Cold-start rattling indicates worn plastic timing chain guides
  • • Chain stretch can cause misfire codes and loss of power
  • • Immediate specialist diagnosis prevents interference damage
  • • Towing to workshop is far cheaper than post-failure rebuild
Important

Driving with a rattling timing chain risks bent valves, piston damage, and total engine seizure.

-> Book urgent BMW 3 Series 320i timing chain diagnosis with a specialist now

Question 4

How long does a rebuilt BMW 3 Series 320i engine last?

A properly rebuilt BMW 3 Series 320i engine with upgraded failure-point components typically lasts 80,000-120,000 miles when maintained with correct oil specifications and service intervals.

Key points

  • • Upgraded metal timing chain guides prevent repeat N20 failure
  • • Synthetic oil changes every 10k miles maximise longevity
  • • Bench testing and ECU matching ensure optimal performance
  • • 12-month unlimited mileage warranty provides immediate peace of mind
  • • Get quotes for long-life rebuilt BMW 3 Series 320i engines today
-> Get quotes for long-life rebuilt BMW 3 Series 320i engines today

Question 5

Do BMW 3 Series 320i engine specialists offer vehicle collection?

Yes - most certified BMW 3 Series 320i engine specialists in the EngineMarket network provide vehicle collection and drop-off recovery services nationwide, collecting your non-running car and delivering it back post-repair.

Key points

  • • Collection service included in most specialist quotes
  • • Recovery vehicles transport your 320i safely to workshop
  • • Drop-off delivery returns your car fully repaired and tested
  • • No need to arrange separate towing or transport
  • • Find BMW 3 Series 320i specialists with collection service near you
-> Find BMW 3 Series 320i specialists with collection service near you

Question 6

Is it worth replacing the engine on a high-mileage BMW 3 Series 320i?

Yes - if your BMW 3 Series 320i is otherwise in good condition, a rebuilt engine costing £2,300-£3,800 often represents better value than purchasing a replacement vehicle with unknown history.

Key points

  • • Compare rebuild cost against current market value of your 320i
  • • Rebuilt engine restores performance and extends usable life
  • • Avoid depreciation hit of buying another used premium car
  • • Warranty protection reduces future financial risk
  • • Calculate whether engine replacement makes financial sense for your 320i
-> Calculate whether engine replacement makes financial sense for your 320i

Question 7

What's the difference between N20-B20B and B48-B20A engines in the BMW 3 Series 320i?

The N20-B20B (2012-2018) uses plastic timing chain guides prone to wear, while the B48-B20A (2015-2024) features improved metal guides and enhanced thermal management for greater reliability.

Key points

  • • N20-B20B requires upgraded metal guides during rebuild
  • • B48-B20A has fewer documented timing-related failures
  • • Both engines share similar power output (~184 PS)
  • • Correct engine code identification ensures parts compatibility
  • • Verify your BMW 3 Series 320i engine code before requesting quotes
-> Verify your BMW 3 Series 320i engine code before requesting quotes

Question 8

Where can I find a trusted BMW 3 Series 320i N20-B20B engine specialist near me?

EngineMarket connects you with vetted UK BMW 3 Series 320i N20-B20B specialists nationwide. Most network partners offer vehicle collection and drop-off recovery services - they will collect your non-running 3 Series 320i, complete the engine replacement in their workshop, and deliver it back. Compare live quotes from certified rebuilders who understand your 320i's specific N20-B20B requirements - all backed by minimum 12-month unlimited mileage warranty.

Key points

  • • Vetted BMW 3 Series 320i N20-B20B specialists rated by real UK owners
  • • Vehicle collection and drop-off recovery available from most network suppliers nationwide
  • • Live price comparison for rebuilt, reconditioned and used N20-B20B units
  • • Minimum 12-month unlimited mileage warranty on every engine supplied
  • • Transparent quotes with no hidden fees or obligation to proceed
  • • Get quotes from BMW 3 Series 320i N20-B20B specialists near you today
-> Get quotes from BMW 3 Series 320i N20-B20B specialists near you today

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 EngineMarket carries a minimum 12-month unlimited mileage warranty - always confirm terms with your chosen supplier.

Why Choose Us

Why UK BMW 3 Series 320i Owners Trust EngineMarket

Compare quotes from trusted UK BMW 3 Series 320i engine specialists with warranty-backed rebuilt, reconditioned and used options nationwide.

Vetted BMW 3 Series 320i Specialists

Every rebuilder and garage in our network is rated and reviewed by real owners of your 3 Series 320i.

Transparent Price Comparison

See rebuilt, reconditioned and used engine costs side-by-side before committing, with no hidden fees or obligation.

Nationwide Coverage, Local Recovery

Supply-only delivery across the UK, with vehicle collection and workshop fitting available from specialists near you for hassle-free BMW 3 Series 320i engine replacement.

Find the best BMW 3 Series 320i engine replacement UK drivers rely on.

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

Compare BMW 3 Series 320i Engine Prices Now
BMW 3 Series 320i vehicle

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BMW 3 Series 320i specialists across the UK

Compare supply-only and supply & fit quotes from vetted independent engine specialists.