BMW 4 Series 428i2013–20202 Engine Generations
BMW 4 Series 428i Engine Replacement —Compare Prices &
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Get quotes today from trusted UK BMW 428i specialists. Compare reconditioned, rebuilt and used 2.0-litre turbocharged petrol engines — N20 and B48 variants across the F32 Coupé, F33 Convertible and F36 Gran Coupé — supply & fit available nationwide.
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BMW 4 Series 428i Engines — from £800 to £6,500Common codes: N20B20A, B48B20
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The 428i Through Time — Era Map
Two generations. Two eras. One guide to reliability, costs and what really matters.
Era Note
Pre-2015 N20 timing chain guide failure is the critical weakness
Era Note
B48 replaced N20 at LCI — robust, reliable; timing chain issues resolved
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 4 Series 428i Engine Replacement Costs
- Supply Only£800 – £2,000
- Fitted (Indie)£1,400 – £3,200
- Warranty1–6 months
- Best ForBudget priority; vehicle under £8,000
- Supply Only£3,500 – £5,500
- Fitted (Indie)£4,300 – £6,700
- Warranty12–24 months
- Best ForMost owners — best cost/warranty balance
- Supply Only£4,500 – £6,500
- Fitted (Indie)£5,300 – £7,700
- Warranty12–24 months
- Best ForLong-term ownership; 3+ year horizon
- Supply Only£8,000 – £12,000
- Fitted (Indie)£9,500 – £14,000
- Warranty24–36 months
- Best ForInsurance jobs, warranty claims
Figures above reflect current 428i replacement costs. The B48 variant typically sits at the higher end of the range. See the Era Map above for generation-specific pricing.
Labour estimate: Fitting a 428i engine typically takes 10–14 hours at £65–£95/hr (independent) or £110–£160/hr (London/SE dealer).
Common Problems With BMW 4 Series 428i Engines
2. Oil Leaks(Valve Cover & Oil Filter Housing — N20)
3. Water Pump & Cooling System Issues(N20 & B48)
Weighing Your Options?
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4 Series 428i — 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 |
|---|---|---|---|
| Timing chain rattle (N20 — preventative) | Yes | £1,500 – £3,000 | Essential maintenance — catch it before catastrophic failure |
| Snapped timing chain (N20) | Usually No | Engine replacement | Piston-valve contact means little is left to repair |
| Oil leaks (valve cover, oil filter housing) | Yes | £300 – £800 | Straightforward gasket replacements |
| Water pump failure (N20 & B48) | Yes | £400 – £900 | Catch it early — before overheating |
| Head gasket failure (from overheating) | Yes | £1,000 – £2,500 | Worth it on a well-maintained 4 Series |
ProblemRepairable? · Typical Cost
Timing chain rattle (N20 — preventative)
Yes£1,500 – £3,000
Essential maintenance — catch it before catastrophic failure
Snapped timing chain (N20)
Usually NoEngine replacement
Piston-valve contact means little is left to repair
Oil leaks (valve cover, oil filter housing)
Yes£300 – £800
Straightforward gasket replacements
Water pump failure (N20 & B48)
Yes£400 – £900
Catch it early — before overheating
Head gasket failure (from overheating)
Yes£1,000 – £2,500
Worth it on a well-maintained 4 Series
Buying This 428i? Check These First
Buy if:
- Post-LCI (2017+) with the B48 engine (significantly more reliable)
- Pre-LCI (2013–2017) with documented timing chain guide replacement
- Full service history with regular oil changes (critical for chain longevity)
- No cold-start rattling (listen carefully on first start)
- No oil leaks around the oil filter housing or valve cover
Avoid if:
- Pre-LCI N20 with cold-start rattle and no chain history — assume it's overdue
- No service history — the N20 is unforgiving of neglect
- Oil leaks around the oil filter housing (belt damage risk)
- Overheating history or unexplained coolant loss — may indicate water pump or head gasket issues
Closing verdict
The 428i is BMW's entry-level 2.0-litre turbocharged petrol in the first-generation 4 Series. The N20 (pre-LCI, 2013–2017) is a capable engine let down by one critical design flaw — timing chain guide failure. The B48 (LCI, 2017–2020) is a significant improvement, resolving the chain issues and offering greater reliability. With typical F32/F33/F36 values ranging from £8,000 to £20,000+, a £4,000–£5,500 engine replacement is a significant investment. A post-2017 B48-engined car is the safer choice.
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Buying Checklist
Before you buy a used BMW 4 Series 428i (or before you commit to an engine replacement), check these:
1. Cold Start
Listen for rattling (N20 timing chain guide warning) — see the map above
2. Service History
Including which engine era (N20 or B48) and oil-change discipline
3. Timing Chain
For N20 (pre-LCI): check for any chain work or cold-start rattle
4. Oil Leaks
Check around valve cover and oil filter housing for leaks
5. Coolant Level
Check reservoir when cold; any low or loss may indicate water pump issues
6. Turbo Health
Test acceleration; any lag, whistling, or hesitation?
7. Engine Warning Light
Have codes been read? Any unresolved issues?
8. MOT History
Check for emissions-related failures
Buying Checklist
Before you buy a used BMW 4 Series 428i (or before you commit to an engine replacement), check these:
- 1
Cold Start
Listen for rattling (N20 timing chain guide warning) — see the map above
- 2
Service History
Including which engine era (N20 or B48) and oil-change discipline
- 3
Timing Chain
For N20 (pre-LCI): check for any chain work or cold-start rattle
- 4
Oil Leaks
Check around valve cover and oil filter housing for leaks
- 5
Coolant Level
Check reservoir when cold; any low or loss may indicate water pump issues
- 6
Turbo Health
Test acceleration; any lag, whistling, or hesitation?
- 7
Engine Warning Light
Have codes been read? Any unresolved issues?
- 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 4 Series 428i pitfalls.
Engine Codes
This table's rows match Section 1B's Era Map exactly.
N20B20A
- Years
- 2013–2017 (F32/F33/F36 pre-LCI)
- Power
- 245 PS (180 kW) @ 5,000rpm
- 2025 Enquiries
- —(within N20 family volume)
- Avg. Recon Cost
- £3,500–£5,500[PLACEHOLDER]
B48B20
- Years
- 2017–2020 (F32/F33/F36 LCI)
- Power
- 252 PS (185 kW)
- 2025 Enquiries
- —(within B48 family volume)
- Avg. Recon Cost
- £4,000–£6,500[PLACEHOLDER]
Technical SpecsB48B20 — LCI generation
- Displacement
- 1,997cc
- Cylinders
- 4-cylinder inline, aluminium block
- Compression Ratio
- 10.0:1
- Fuel System
- Direct injection, single twin-scroll turbocharger
- Valvetrain
- DOHC, Double-VANOS, Valvetronic
- Torque
- 350 Nm @ 1,250–4,800 rpm
- Displacement
- 1,998cc
- Cylinders
- 4-cylinder inline, aluminium block
- Fuel System
- Direct injection, twin-scroll turbocharger
- Torque
- 400 Nm
Market Intelligence
Real data from thousands of 4 Series 428i enquiries in 2025.
Most Common FailureN20 timing chain guide failure (pre-LCI)
The defining issue of the earlier 428i
Average Enquiry Mileage
50,000–70,000
miles
[PATTERN DATA]Average Replacement Cost
£4,000–£5,000
reconditioned, supply only
[PLACEHOLDER]Most Requested Engine Code
N20B20A
[PATTERN DATA]Peak Enquiry Season
Winter
Cold starts expose timing chain wear
[PATTERN DATA]Regional Demand
- South East
- 18%
- North West
- 16%
- Midlands
- 14%
- Other Regions
- 52%
Regional Demand Breakdown
14%Midlands18%South East16%North West52%Other Regions
Frequently Asked Questions
A reconditioned 428i engine typically costs £3,500–£5,500 supply only, with the B48 variant at the higher end. Fitting adds £800–£1,300 depending on the specialist. A blown engine replacement on a BMW can cost between £9,000 and £13,000. Used engines can be found from £800–£2,000. Use our calculator for a figure specific to your 4 Series.
It depends on which engine era your 428i has. The pre-LCI N20 (2013–2017) has a well-documented timing chain guide failure risk — plastic guides can disintegrate, causing catastrophic engine failure. The LCI B48 (2017–2020) is a significant improvement, with the timing chain issues resolved. The N20 also suffers from oil leaks and water pump issues. A post-2017 B48-engined car is the safer choice.
The main issues are timing chain guide failure on the N20 (pre-LCI) — plastic guides become brittle and break, oil leaks from the valve cover and oil filter housing, water pump failure (particularly on the N20, with a fire risk recall), and occasional turbocharger wastegate rattle. The B48 (LCI) is significantly more reliable.
Depends on the generation and vehicle condition. Against a well-kept F32/F33/F36 worth £8,000–£15,000, a £4,000–£5,500 recon is 25–60% of the car's value — often worth it for a cherished example. Against a tired pre-LCI car with significant body issues, the same recon may exceed our 70% BMW threshold — get a scrap valuation first. B48-engined cars command a premium due to improved reliability.
Pre-LCI F32/F33/F36 (2013–2017) 428i engines carry the N20B20A code. LCI F32/F33/F36 (2017–2020) use the B48B20 code. Check the VIN plate or vehicle documentation. If your car is registered after mid-2017, it's almost certainly the B48.
The chain guides must be replaced — they are the weak point. A preventative replacement of the timing chain and guides costs £1,500–£3,000. A snapped chain almost always destroys the engine, requiring a £3,500–£5,500+ replacement. At the first sign of cold-start rattle, book an inspection 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 condition, 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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