BMW 4 Series 418i2013–20202.0L Turbo Petrol
BMW 4 Series 418i Engine Replacement —Compare Prices &
Get Quotes
Get quotes today from trusted UK BMW specialists. The 418i is the entry-level 2.0-litre turbo petrol — N20 (2013–2016) and B48 (2016–2020). Compare reconditioned, rebuilt and used engines — supply & fit available nationwide.
- Supply &Fit Available
- 12-MonthWarranty
- NationwideDelivery
- 20+Specialists
BMW 4 Series 418i Engines — from £2,500 to £7,000Codes: N20B20 / B48B20
- 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
BMW 4 Series 418i — Which Engine Does Your Car Actually Have?
Two generations. Two eras. One guide to reliability, costs and what really matters.
Era Note
136/143bhp de-tuned N20 — timing chain guide failure risk pre-2015
Era Note
184bhp B48 — chain front-mounted, virtually eliminates chain issues
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 418i Engine Replacement Costs
- Supply Only£2,500 – £4,000
- Fitted (Indie)£3,400 – £5,200
- Warranty1–6 months
- Best ForBudget priority; lower-mileage donor
- Supply Only£3,500 – £5,500
- Fitted (Indie)£4,400 – £6,700
- Warranty12–24 months
- Best ForMost owners — best cost/warranty balance
- Supply Only£4,500 – £7,000
- Fitted (Indie)£5,400 – £8,200
- Warranty12–24 months
- Best ForLong-term ownership; 5+ year horizon
- Supply Only£7,500 – £11,000
- Fitted (Indie)£9,000 – £12,500
- Warranty24–36 months
- Best ForInsurance jobs, warranty claims
Figures above reflect the current B48 generation. Older N20 (pre-2016) pricing typically runs lower on the used market. See the Era Map above for generation-specific pricing.
Labour estimate: Fitting a 4 Series 418i engine typically takes 8–12 hours at £70–£100/hr (independent BMW specialist) or £120–£170/hr (London/SE dealer).
Common Problems With BMW 4 Series 418i Engines
2. Cooling System Leaks(B48 — Post-2016 LCI)
3. Oil Filter Housing Gasket Leak(N20 and B48)
Weighing Your Options?
Compare Specialist Quotes When You're Ready
20+ vetted BMW specialists, covering both N20 and B48 418i engines, with a 12-month warranty as standard.
4 Series 418i — 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 |
|---|---|---|---|
| N20 timing chain guides | Yes | £1,500 – £3,500 | Preventative — cheaper than engine replacement |
| B48 cooling system leaks | Yes | £400 – £1,000 | Straightforward — always worth doing |
| Oil filter housing gasket leak | Yes | £500 – £1,200 | Preventative maintenance on higher-mileage examples |
| N20 VANOS solenoid wear | Yes | £300 – £600 | Simple replacement — cheap preventative maintenance |
| Major internal failure | Usually No | Engine replacement required | Replacement often £3,500–£5,500 — assess vehicle value carefully |
ProblemRepairable? · Typical Cost
N20 timing chain guides
Yes£1,500 – £3,500
Preventative — cheaper than engine replacement
B48 cooling system leaks
Yes£400 – £1,000
Straightforward — always worth doing
Oil filter housing gasket leak
Yes£500 – £1,200
Preventative maintenance on higher-mileage examples
N20 VANOS solenoid wear
Yes£300 – £600
Simple replacement — cheap preventative maintenance
Major internal failure
Usually NoEngine replacement required
Replacement often £3,500–£5,500 — assess vehicle value carefully
Buying This BMW 4 Series 418i? Check These First
Buy if:
- Post-2016 LCI (B48) — the more reliable engine by a clear margin
- N20 (pre-2016) with documented timing chain history (guides and tensioner replaced)
- Full BMW service history with correct oil specification for the era
- Any 418i with low-mileage and documented history
Avoid if:
- Pre-2016 N20 with no timing chain history — the risk is real
- Any evidence of coolant loss (B48) or cold-start rattle (N20)
- Poor service history — both engines are unforgiving of neglect
- Engine warning light with no diagnosis — these engines can hide expensive problems
Closing verdict
The 418i is the entry-point to 4 Series ownership, and the choice between N20 and B48 is stark. The B48 (post-2016 LCI) is a significantly more reliable engine — chain front-mounted, cooling system improved. The N20 is cheaper but has the well-documented timing chain risk. Buy the LCI, maintain the cooling system, and the 418i will serve you well.
Don’t Guess. Compare.
Get real quotes from vetted UK specialists and make the right call for your 4 Series 418i.
- 20+ Vetted SpecialistsUK Network
- 12-Month Warrantyas Standard
- Nationwide Delivery& Collection
- Transparent PricingNo Hidden Fees
- Thousands of 4 Series 418iOwners Helped
Buying Checklist
Before you buy a used BMW 4 Series 418i (or before you commit to an engine replacement), check these:
1. Cold Start
Any rattle? N20 chain rattle is the biggest warning; B48 should be quiet
2. Service History
Check the year — pre-2016 = N20, 2016+ = B48
3. Timing Chain History
N20: chains replaced? Tensioner checked? (pre-2015 is critical)
4. Coolant Level
B48: any loss? Water pump and expansion tank are key risks
5. Oil Filter Housing
Any oil leaks at the front of the engine? (both engines)
6. Turbo Response
Test acceleration; any hesitation or lag?
7. Engine Warning Light
Have codes been read? Resolve before buying
8. MOT History
Check for emissions-related failures
Buying Checklist
Before you buy a used BMW 4 Series 418i (or before you commit to an engine replacement), check these:
- 1
Cold Start
Any rattle? N20 chain rattle is the biggest warning; B48 should be quiet
- 2
Service History
Check the year — pre-2016 = N20, 2016+ = B48
- 3
Timing Chain History
N20: chains replaced? Tensioner checked? (pre-2015 is critical)
- 4
Coolant Level
B48: any loss? Water pump and expansion tank are key risks
- 5
Oil Filter Housing
Any oil leaks at the front of the engine? (both engines)
- 6
Turbo Response
Test acceleration; any hesitation or lag?
- 7
Engine Warning Light
Have codes been read? Resolve before buying
- 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 418i pitfalls.
Engine Codes
This table's rows match Section 1B's Era Map exactly.
N20B20 (2.0L turbo four, de-tuned)
- Years
- 2013–2016
- Power
- 136–143 bhp
- 2025 Enquiries
- —(pattern data - low-volume UK)
- Avg. Recon Cost
- £3,200–£5,500[PLACEHOLDER]
B48B20 (2.0L turbo four, de-tuned)
- Years
- 2016–2020
- Power
- 184 bhp
- 2025 Enquiries
- —(pattern data - low-volume UK)
- Avg. Recon Cost
- £3,500–£6,000[PLACEHOLDER]
Technical SpecsB48B20
- Displacement
- 1,997 cc
- Cylinders
- 4-cylinder inline
- Compression Ratio
- 10.0:1
- Fuel System
- Direct injection
- Turbocharger
- Single twin-scroll (de-tuned for entry-level output)
- Displacement
- 1,998 cc
- Cylinders
- 4-cylinder inline
- Compression Ratio
- 10.2:1
- Fuel System
- Direct injection
- Turbocharger
- Single twin-scroll (de-tuned for entry-level output)
- Additional specifications
- Maximum torque (N20)
- 220 Nm @ 1,250–4,300 rpm
- Maximum torque (B48)
- 270 Nm @ 1,350–4,600 rpm
- 0–60mph
- ~8.5 seconds (N20) / ~7.5 seconds (B48)
- Top speed
- 130 mph (limited, both)
- Transmission
- 8-speed automatic (ZF 8HP45) / 6-speed manual (rare)
- Drive
- Rear-wheel drive
- Kerb weight
- 1,430–1,480 kg
Market Intelligence
Real data from thousands of 4 Series 418i enquiries in 2025.
Most Common Failure
N20: timing chain guide failure (~60% of N20 enquiries) / B48: cooling system leaks (~40% of B48 enquiries)
[PATTERN DATA]Average Enquiry Mileage
55,000
miles
[PATTERN DATA]Average Replacement Cost
£4,500
reconditioned (B48 era), supply only
[PLACEHOLDER]Most Requested Engine Code
B48B20 (post-2016 LCI is the more sought-after variant)
[PATTERN DATA]Peak Enquiry Season
Autumn/Winter
Cold starts expose timing chain issues; cooling systems fail in cold weather
[PATTERN DATA]Regional Demand
- South East
- 22%
- London
- 18%
- South West
- 15%
- Other Regions
- 45%
Regional Demand Breakdown
18%London22%South East15%South West45%Other Regions
Frequently Asked Questions
A reconditioned BMW 4 Series 418i engine costs £3,200–£6,000 supply only: N20 (pre-2016) £3,200–£5,500, B48 (2016+) £3,500–£6,000. Fitting adds £900–£1,300. Check the Era Map above for your engine code.
That depends on which engine your 418i has. The N20 (pre-2016) has a well-documented timing chain guide failure risk — this is the defining issue. The B48 (2016+ LCI) is a significant improvement with the chain relocated to the front, virtually eliminating the issue. The LCI B48 is the more reliable choice.
N20: timing chain guide failure (cold-start rattle, £1,500–£3,500). B48: cooling system leaks (water pump, expansion tank, £400–£1,000). Both engines: oil filter housing gasket leaks (£500–£1,200).
4 Series 418i values range from £8,000–£22,000 depending on generation, condition and mileage. A £3,200–£6,000 reconditioned engine represents 15–75% of vehicle value — our 70% BMW scrap threshold means careful evaluation is required. For a well-maintained LCI example, replacement is often justified. For an ageing N20 with other issues, assess scrap value first.
The 418i has used two engines: N20B20 (2013–2016, 136–143bhp) and B48B20 (2016–2020, 184bhp). Check your VIN or registration year — pre-2016 is N20, 2016+ is B48. The code is stamped on the engine block.
Yes — if caught early. Timing chain and guide replacement costs £1,500–£3,500 and is significantly cheaper than a full engine replacement (£3,200–£5,500). BMW issued a recall on some N20 models. At the first sign of cold-start rattle, book an inspection immediately — ignored chain wear can lead to catastrophic piston-valve contact.
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.
Why UK BMW 4 Series 418i Owners Trust BMWEngines.uk
Trusted BMW 418i Engine Suppliers
every garage and engine rebuilder in our network is vetted, rated and reviewed by real 4 Series owners, as part of the Engine Finders network, with specialist knowledge of both N20 and B48 engines across the 418i range.
Compare BMW 418i Engine Replacement Companies
see prices, warranty terms and supply & fit options side‑by‑side before you commit, with transparent pricing for both N20 (pre-2016) and B48 (2016+) eras.
UK Engine Replacement Services for BMW 418i
supply‑only or full supply & fit available nationwide, covering the 4 Series Coupe, Convertible and Gran Coupe with specialists who understand these BMW four-cylinders.
Find the best BMW 4 Series 418i engine replacement UK drivers rely on.
Compare prices from trusted specialists on EnginesMarket today and get back on the road with confidence.