BMW 3 Series 320i Engine ReplacementCompare Prices & Get Quotes
Get quotes today from trusted UK BMW 3 Series 320i engine specialists. Compare prices on reconditioned, rebuilt and used engines for every 320i generation - from the E46 M54 to the G20 B48.
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12-Month Warranty
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100+ Suppliers
From £3,800 to £6,000
Used from £1,500 · Reconditioned from £2,800 · Common codes: M54B22, N46B20, N43B20A, N20B20A, N20B20B, B48B20A
From £1,500
Tested, bare/short engine
From £2,800
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 3 Series 320i Replacement Engineto Finding the Best BMW 3 Series 320i Replacement Engine
Most replacements completed within 3-5 days.
Variant HistoryBMW 3 Series 320i - Engine History & Specs at a Glance
The BMW 320i has been the heart of the 3 Series petrol range since the E21 generation launched in 1975. Over five decades, the 320i badge has moved from a carburettor-fed four-cylinder to a six-cylinder M54, then back to four-cylinder N-series engines, and finally to the modern modular B48 turbo - each generation bringing more power, efficiency and complexity.
Variant HistoryBMW 3 Series 320i - Engine History & Specs at a Glance
The BMW 320i has been the heart of the 3 Series petrol range since the E21 generation launched in 1975. Over five decades, the 320i badge has moved from a carburettor-fed four-cylinder to a six-cylinder M54, then back to four-cylinder N-series engines, and finally to the modern modular B48 turbo - each generation bringing more power, efficiency and complexity.
BMW 3 Series 320i
Fuel TypePetrol
Engine Size Range2.0L-2.2L
Power Output Range120-184hp across the variant's historyEngine History Timeline
M10B20 2.0-litre four-cylinder, fuel-injected (123hp) - E21 generation
M20B20 2.0-litre six-cylinder (120hp) - E21 generation, carburettor
M20B20 2.0-litre six-cylinder (125hp) - E30 generation
M50B20 2.0-litre straight-six (150hp) - E36 generation, DOHC
M52TUB20 2.0-litre straight-six (150hp) - E46 generation, double VANOS
M54B22 2.2-litre straight-six (170hp) - E46 facelift, increased displacement
N46B20 2.0-litre four-cylinder (150hp) - E90 generation, Valvetronic
N43B20A 2.0-litre four-cylinder (170hp) - E90/E92 generation, direct injection
N20B20A/B 2.0-litre four-cylinder turbo (184hp) - F30 generation, TwinPower Turbo
B48B20A 2.0-litre four-cylinder turbo (181hp) - F30 LCI / G20 generation, modular engine
B48B20B 2.0-litre four-cylinder turbo (184hp) - G20 generation, updated
Key Specs Snapshot
Fuel TypePetrolEngine Size Range2.0L-2.2LPower Output Range120-184hp across the variant's historyYears Produced1975-presentEvery engine fitted to the BMW 3 Series 320i is covered below, with UK rebuilt pricing and known failure points.
BMW 3 Series 320i Engine Codes - Specifications & Replacement CostBMW 3 Series 320i Engine Codes - Specifications & Replacement Cost
2.2L Petrol (2000-2005)
Power Output170hpYears Fitted2000-2005
Compatible Trim Levels
- 320i
- 320i SE
- 320i Sport
- 320i M Sport
Find your exact engine code, specs and UK replacement cost guide.
Used
Tested, ready-to-fit engine
£400-£900
Reconditioned
Addressed known issues, tested
£1,200-£2,200
Rebuilt
Full teardown, upgraded internals
£2,000-£3,200
Common Failure
VANOS solenoid failure and oil leaks from the valve cover gasket are common on higher-mileage M54 units. Cooling system components (water pump, expansion tank) also degrade with age.
The BMW 3 Series 320i's petrol engines have evolved significantly over the years, but several recurring failure points drive replacement demand. The N43 and N20 timing chain issues are the most common reasons 320i owners seek engine replacement, while the B48's cooling system problems typically require less drastic intervention. Rebuilt engines through EnginesMarket include upgraded components addressing the original failure point, plus a minimum 12-month unlimited-mileage warranty.
Why the BMW 3 Series 320i N43 and N20 Engines Wear Prematurely
Affected Vehicles
BMW 3 Series 320i (N43B20A, 2007-2012; N20B20A/B, 2012-2015)
Typical Failure Mileage
30,000-90,000 miles
Root Cause
The timing chain tensioner was underspecified, allowing the chain to slacken and rub against - or break - the plastic guides. On interference engines, a skipped tooth means valve-to-piston contact and catastrophic failure.
Why It Happens
The timing chain tensioner was underspecified, allowing the chain to slacken and rub against - or break - the plastic guides. On interference engines, a skipped tooth means valve-to-piston contact and catastrophic failure.
Dealer (parts + labour)
£1,500-£2,500
Specialist (parts + labour)
£800-£1,500
What it involves
Replace tensioner, guides and chain. Oil pan drop to remove guide debris.
Suitability
Best if caught early - rattle on start-up but no performance loss
1 - 2 daysDealer (parts + labour)
£5,000-£8,000
Specialist (parts + labour)
£2,500-£4,500 (matches Section 4 rebuilt pricing)
What it involves
Supply & fit, upgraded timing components addressing the original failure point, 12-month warranty
Suitability
If timing has jumped or engine is damaged
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 |
|---|---|---|---|---|---|
 Timing chain replacement (preventative) Minor | £1,500-£2,500 | £800-£1,500 | Replace tensioner, guides and chain. Oil pan drop to remove guide debris. | Best if caught early - rattle on start-up but no performance loss | 1 - 2 days |
 Full Replacement - rebuilt/reconditioned engine Best Value | £5,000-£8,000 | £2,500-£4,500 (matches Section 4 rebuilt pricing) | Supply & fit, upgraded timing components addressing the original failure point, 12-month warranty | If timing has jumped or engine is damaged | 1 - 2 days |
Vehicle Value Check
Vehicle Value Check
A typical BMW 3 Series 320i of N43/N20 age (2007-2015) is worth approximately £3,000-£10,000 depending on mileage and condition [THIRD-PARTY]. For sub-£4,000 examples, a used engine or timing chain repair may offer better value than a full rebuilt unit. For cars worth £6,000+, a rebuilt engine with warranty is a sound investment if you plan to keep the car.
Our Recommendation
Our Recommendation
If you hear a rattling noise from the front of the engine on cold start, get it inspected immediately. Replacing the timing chain and tensioner before failure costs £800-£1,500 at a specialist and can save your engine. If the engine has already jumped timing, a full replacement is usually the most cost-effective route - a specialist rebuild with upgraded components costs less than a dealer replacement and carries a 12-month warranty.
Don't Let Engine Failure Write Off Your BMW 3 Series 320i
Whether you own an E46 M54, an E90 N43, an F30 N20, or a G20 B48, engine failure doesn't have to mean the end of the road. Every rebuilt BMW 3 Series 320i engine through EnginesMarket comes with upgraded components addressing the original failure points, a minimum 12-month unlimited-mileage warranty, and nationwide delivery. Compare specialist prices today - and save thousands over main dealer rates.
Compare rebuilt N43/N20 BMW 3 Series 320i engine prices
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 3 Series 320i. Every engine supplied through EnginesMarket carries a minimum 12-month unlimited mileage warranty - always confirm exact terms with your chosen supplier."
BMW 3 Series 320i Engine ReplacementFrequently Asked Questions
Question 1How much does a BMW 3 Series 320i engine replacement cost in the UK-
A BMW 3 Series 320i engine replacement typically costs between £1,800 and £6,000 supply-only, depending on the engine code and condition type.
- Used engines: £400-£1,500 (older codes) to £1,500-£2,800 (B48)
- Reconditioned engines: £1,000-£4,500
- Rebuilt engines: £1,800-£6,000 with 12-month warranty
Question 2What are the signs of timing chain failure in a BMW 3 Series 320i-
On N43 and N20 320i engines, the key warning signs are:
- A rattling or clacking noise from the front of the engine on cold start
- A whining noise that increases with engine RPM
- Rough idle or misfires
- Engine management light with timing-related fault codes
Question 3Is it worth replacing the engine in a BMW 3 Series 320i-
It depends on the age and value of your car:
- E46 320i (worth £1,500-£5,000): repair if possible; full rebuild only if the car is exceptional
- E90 320i (worth £2,500-£8,000): timing chain repair or used engine often makes sense
- F30 320i (worth £5,000-£14,000): rebuilt engine with warranty is usually a sound investment
- G20 320i (worth £15,000+): replacement cost is small relative to vehicle value
Question 4What's the difference between the BMW 320i and 330i engines-
The 320i and 330i share the same B48 engine family but with different tuning:
- 320i (B48B20A): 181-184hp
- 330i (B48B20B): 248hp
Question 5How long does a BMW 3 Series 320i engine replacement take-
A typical BMW 3 Series 320i engine replacement takes 2-5 working days:
- E46/E90 (M54/N46/N43): 10-14 hours labour - around 2-3 days
- F30/G20 (N20/B48): 8-12 hours labour - around 2-3 days
Question 6Does a rebuilt BMW 3 Series 320i engine come with a warranty-
Yes. Every rebuilt BMW 3 Series 320i engine supplied through EnginesMarket comes with a minimum 12-month unlimited-mileage warranty as standard.
- The warranty covers manufacturing defects and parts failure
- Upgraded components address the original failure points (e.g. improved timing chain tensioners on N43/N20)
- Always confirm exact warranty terms with your chosen supplier
Why Choose UsCompare BMW 3 Series 320iEngine PricesToday
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Comparing quotes for your BMW 3 Series 320i is free, quick, and completely no-obligation. Whether you need a used M54B22 for an E46, a reconditioned N43B20A for an E90, or a rebuilt B48B20A for a G20, our network of UK specialists has the right engine for your exact 320i and engine code. Enter your registration above and start comparing today.
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