How much does a BMW 4 Series F36 engine replacement cost in the UK?

A reconditioned F36 engine typically costs £2,000–£14,000 supply only, depending on engine -the four-cylinder petrol sits at £2,000–£4,500, while the S55 in the M4 can reach £8,000–£14,000. Fitting adds £520–£1,430. Use our calculator for a personalised figure.

What are the common problems with the BMW 4 Series F36?

Timing chain guide failure on the N20 four-cylinder petrol, timing chain stretch on the N47 diesel, PCV valve and water pump issues on the B58, crank hub and rod bearing issues on the S55 M4, and -unrelated to the engine -the occasional electrical gremlins and suspension component wear.

Is the BMW 4 Series F36 reliable?

Reliability varies significantly by engine choice. The B58 and B48 are the most dependable, while the N20 and N47 have well-documented timing chain issues. The S55 in the M4 is a high-performance engine that demands meticulous maintenance. A well-maintained F36 can be a rewarding car; a neglected one will be expensive.

Which BMW 4 Series F36 engine should I avoid?

The N20 four-cylinder (pre-2016 420i/428i) without documented timing chain guide replacement -failure is catastrophic and expensive. The N47 diesel (pre-2015 418d/420d/425d) without timing chain history is also a risky purchase. No engine is inherently bad, but history is everything.

How do I know if my F36 engine needs replacing?

Whining noise from the engine (N20 timing chain), cold-start rattle (N47 timing chain), overheating with no obvious external leak (cooling system failure), increased oil consumption (B58 PCV valve), or rough idle and check engine lights are the key warning signs. Use our diagnostic calculator for a personalised assessment.

Is it worth replacing a BMW 4 Series F36 engine, or should I scrap the car?

Depends on the car's value. Against a £12,000 F36, a £5,000 B58 recon is 42% -within our 70% BMW threshold. Against a well-kept £18,000+ example, the same recon is 22–28% -a routine repair decision. Against a sub-£8,000 high-mileage example, a major engine failure is borderline. On an M4, the calculus is different -the car's value justifies the S55's high replacement cost.

How long do BMW 4 Series F36 engines last?

The B58 can exceed 150,000–200,000 miles with proper maintenance. The B48 is similarly durable. The N20 and N47's limiting factor is the timing chain -addressed proactively, either can reach high mileage. The S55 is robust but requires crank hub and rod bearing preventative work.

What is the difference between the F36 and the F32?

The F36 is the Gran Coupé (five-door liftback) variant of the first-generation 4 Series (2014–2020), offering coupé styling with the practicality of a 5-door fastback. The F32 is the 2-door coupé variant, with a shorter wheelbase and lower weight. Both share the same engine range and platform.

How do I find my BMW 4 Series F36 engine code?

Listed on the VIN plate and vehicle documentation; block stamping is visible on the engine itself. Tell us your variant (420i, 430i, 440i, M4, 420d, etc.) and approximate registration date and we'll identify it -20+ vetted specialists will confirm it for free.

BMW 4 Series F36Gran Coupé2014–2020

BMW 4 Series F36 Engines — The Complete UK Guide

Every engine fitted to the F36 Gran Coupé — from the N47 diesel four to the B58 straight-six and the S55-powered M4.

Real UK replacement costs, honest failure data, and the N47 timing chain risk that every Gran Coupé buyer must know.

Explore F36 Engines

Classic Model -Pattern Data
Gran Coupé
14+Engine Codes
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Classic Model -Pattern Data
Gran CoupéBody Style
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Engine Database

BMW 4 Series F36 Engine Codes — The Complete Database

Every engine fitted to the F36 Gran Coupé — from the four-cylinder petrol and diesel units to the six-cylinder N55, B58 and the S55 in the M4.

Engine CodeFuelPowerYearsReliabilityEnquiries (2025)Avg. Recon Cost

B38A15M0B38PetrolTurbo134 bhp2016–2019★★★★☆PATTERN DATA—(pattern data)£2,000–£3,500[PLACEHOLDER]

N20B20N20PetrolTurbo181–241 bhp2014–2016★★★☆☆PATTERN DATA—(pattern data)£2,200–£4,000[PLACEHOLDER]

B48B20B48PetrolTurbo181–248 bhp2016–2020★★★★☆PATTERN DATA—(pattern data)£2,500–£4,500[PLACEHOLDER]

N55B30M0N55PetrolTurbo302 bhp2014–2016★★★★☆PATTERN DATA—(pattern data)£3,500–£6,000[PLACEHOLDER]

B58B30M0B58PetrolTurbo322 bhp2016–2020★★★★★PATTERN DATA—(pattern data)£4,000–£7,000[PLACEHOLDER]

S55B30S55PetrolTwin-turbo425–493 bhp2014–2020★★★★☆PATTERN DATA—(pattern data)£8,000–£14,000[PLACEHOLDER]

N47D20N47DieselTurbo141–215 bhp2014–2016★★★☆☆PATTERN DATA—(pattern data)£2,500–£4,500[PLACEHOLDER]

B47D20B47DieselTurbo148–221 bhp2015–2020★★★★☆PATTERN DATA—(pattern data)£2,800–£5,000[PLACEHOLDER]

N57D30N57DieselTurbo255–308 bhp2014–2020———

Overview

BMW 4 Series F36 — Overview

The F36 is the Gran Coupé (five-door liftback) variant of BMW's first-generation 4 Series, unveiled at the 2014 Geneva Motor Show and produced from July 2014 to 2020. Built on the same platform as the F32 coupé and F33 convertible, the F36 offers coupé styling with the practicality of a five-door liftback, featuring a fastback rear and a C-pillar located behind the rear doors.

The Gran Coupé shares its engine range with the rest of the F3x family, including four-cylinder and six-cylinder turbocharged petrol and diesel units.

Key Facts

PlatformBMW L7 (shared with F30, F32, F33)
PredecessorNone — first 4 Series Gran Coupé
SuccessorBMW 4 Series G26 Gran Coupé
Sibling Body Styles in this GenerationF32 (coupé), F33 (convertible)

Market Intelligence

As a lower-volume Gran Coupé variant, the F36 is a niche enthusiast vehicle — the 440i with the B58 remains the most sought-after, while the 420d is the most practical daily driver.

04Best & Worst Engines

Best & Worst Engines

Thin-Data Summary

The F36's engine range spans three distinct eras. The B58 3.0-litre straight-six (440i, 2016–2020) is the standout — 322 bhp, 450 Nm of torque, and a reputation for bulletproof reliability that has made it one of BMW's most dependable modern engines. The N55 3.0-litre six (435i, 2014–2016) is also a strong performer but lacks the B58's refinement and efficiency. The B48 2.0-litre four-cylinder (420i, 430i, 2016–2020) is the volume choice — responsive, efficient, and well-proven. The N20 2.0-litre four-cylinder (420i, 428i, 2014–2016) has a known timing chain guide issue that can be catastrophic. The N47 2.0-litre diesel (418d, 420d, 425d, 2014–2016) carries the rear-mounted timing chain risk that defines this era — the later B47 (2015–2020) is a significant improvement. The S55 in the M4 is a high-performance twin-turbo six with 425–493 bhp, but it demands meticulous maintenance and has known crank hub and rod bearing concerns. If you're buying an F36, the B58 is the emotional choice; the B48 is the sensible one; the B47 is for high-mileage drivers; the N20 and N47 require documented history.

Thin-Data Summary

BMW 4 Series F36
Ownership Economics

Engine

Typical Mileage

Common Major Failure

Repair Cost (Specialist)

Replacement Cost (Recon)

Ownership Verdict

B38 1.5 (418i)40k–80kWater pump, cooling system£400–£800£2,000–£3,500

Solid Choice -simple three-cylinder

N20 2.0 (420i/428i)40k–80kTiming chain guides, VANOS£800–£1,800£2,200–£4,000

High Risk -chain guide failure is catastrophic

B48 2.0 (420i/430i)40k–80kWater pump, cooling system£500–£1,200£2,500–£4,500

Best Petrol 4-Cyl -well-proven B48

N55 3.0 (435i)40k–80kHPFP, water pump, VANOS£800–£2,000£3,500–£6,000

Solid Choice -robust but ageing

B58 3.0 (440i)40k–80kPCV valve, water pump, coolant leaks£800–£2,000£4,000–£7,000

Best Overall -the B58 is a modern legend

S55 3.0 (M4)30k–60kCrank hub, rod bearings, water pump£2,000–£5,000£8,000–£14,000

Most Expensive -outstanding performance, outstanding running costs

N47 2.0 Diesel60k–120kTiming chain stretch£1,000–£1,800£2,500–£4,500

Risk vs Reward -chain history essential

B47 2.0 Diesel60k–120kEGR cooler, DPF£600–£1,500£2,800–£5,000

Best Diesel -improved chain design

N57 3.0 Diesel80k–150kTiming chain (N57), EGR, DPF£800–£2,000£4,000–£7,000

Solid Choice -six-cylinder torque

Engine

Typical Mileage

Common Major Failure

Repair Cost (Specialist)

Replacement Cost (Recon)

Ownership Verdict

B38 1.5 (418i)40k–80kWater pump, cooling system£400–£800£2,000–£3,500

Solid Choice -simple three-cylinder

N20 2.0 (420i/428i)40k–80kTiming chain guides, VANOS£800–£1,800£2,200–£4,000

High Risk -chain guide failure is catastrophic

B48 2.0 (420i/430i)40k–80kWater pump, cooling system£500–£1,200£2,500–£4,500

Best Petrol 4-Cyl -well-proven B48

N55 3.0 (435i)40k–80kHPFP, water pump, VANOS£800–£2,000£3,500–£6,000

Solid Choice -robust but ageing

B58 3.0 (440i)40k–80kPCV valve, water pump, coolant leaks£800–£2,000£4,000–£7,000

Best Overall -the B58 is a modern legend

S55 3.0 (M4)30k–60kCrank hub, rod bearings, water pump£2,000–£5,000£8,000–£14,000

Most Expensive -outstanding performance, outstanding running costs

N47 2.0 Diesel60k–120kTiming chain stretch£1,000–£1,800£2,500–£4,500

Risk vs Reward -chain history essential

B47 2.0 Diesel60k–120kEGR cooler, DPF£600–£1,500£2,800–£5,000

Best Diesel -improved chain design

N57 3.0 Diesel80k–150kTiming chain (N57), EGR, DPF£800–£2,000£4,000–£7,000

Solid Choice -six-cylinder torque

The F36 rule

A £4,000–£7,000 B58 recon against a £12,000 F36 sits at 33–58% of the car's value -within our 70% BMW threshold. Against a well-kept £18,000+ example, the same recon drops to 22–39% -a routine repair decision. Against a sub-£8,000 high-mileage example, a major engine failure is borderline. Value the car first.

Key Takeaways

Which F36 Costs Least To Own?
B48 420i -simpler than the sixes, lower running costs.
Which F36 Costs Most To Own?
S55 M4 -crank hub, rod bearings, and specialist-only maintenance.
Which F36 Is Best Value?
B58 440i -bulletproof six-cylinder performance without the M4's running costs.

Common Problems

N20

Timing Chain Guide Failure

Affected models:

F36 420i, 428i (2014–2016, N20 engine).

Typical failure mileage:

40,000–80,000 miles.

Root cause:

The N20's timing chain guides are made of a plastic material that can become brittle and fail over time. When the guides break, the timing chain can slip or snap, causing catastrophic engine damage. A whining noise from the engine, particularly on cold start, is the classic early warning.

Our Recommendation

At the first sign of a whining noise from the engine on an N20-powered F36, get the timing chain inspected immediately. An £800–£1,800 preventative repair is dramatically cheaper than the £2,200–£4,000 replacement that follows if ignored. Avoid pre-2015 N20 cars without documented chain history.

Compare N20 engine prices for your F36

N47

Diesel Timing Chain Stretch

Affected models:

F36 418d, 420d, 425d (2014–2016, N47 engine).

Typical failure mileage:

60,000–120,000 miles.

Root cause:

The N47's timing chain is mounted at the rear of the engine, making it a major labour-intensive job to replace. The chain, guides, and tensioners can wear prematurely, causing chain stretch. If the chain stretches too far, it can "jump" a tooth or snap, causing pistons to strike open valves. Cold-start rattle for 1–2 seconds is the classic early warning.

Our Recommendation

At the first sign of cold-start rattle on an N47 diesel F36, get the timing chain inspected immediately. A £1,000–£1,800 preventative repair is dramatically cheaper than the £2,500–£4,500 replacement that follows if ignored. Consider the B47-equipped cars (2015–2020) which have an improved chain design.

Compare N47 engine prices for your F36

B58

PCV Valve & Cooling System

Affected models:

F36 440i (2016–2020, B58 engine).

Typical failure mileage:

40,000–80,000 miles.

Root cause:

The B58's Positive Crankcase Ventilation (PCV) valve can fail, causing increased oil consumption, rough idle, and check engine lights. The electric water pump also has a finite service life and can fail without warning, leading to overheating. The cooling system uses plastic components that can become brittle with age.

Our Recommendation

Replace the water pump proactively at 60,000–80,000 miles on any B58-powered F36. A £400–£800 preventative job is far cheaper than a £4,000+ engine replacement. Monitor oil consumption and investigate any increase immediately.

Compare B58 engine prices for your F36 440i

S55

Crank Hub & Rod Bearings (M4)

Affected models:

F36 M4 (2014–2020, S55 engine).

Typical failure mileage:

30,000–60,000 miles.

Root cause:

The S55's crank hub can spin on the crankshaft, causing timing to slip and potentially catastrophic engine damage. The rod bearings can also wear prematurely, particularly on cars that have been tracked or driven hard. Both issues are well-documented in the M community.

Our Recommendation

If you own an M4, budget for a crank hub fix and rod bearing replacement as preventative maintenance. A £1,500–£3,000 investment is far cheaper than the £8,000–£14,000 engine replacement that follows a failure. Use the correct oil and warm the engine properly before hard driving.

Compare S55 engine prices for your F36 M4

F36
Engine Replacement Costs -By Engine and Condition

Variant

Engine Code

Used (Supply)

Reconditioned (Supply)

Rebuilt (Supply)

Labour Hours

418iB38A15M0£800–£1,800£2,000–£3,500£3,000–£4,5008–12 hrs

420i / 428i (pre-LCI)N20B20£1,200–£2,500£2,200–£4,000£3,500–£5,50010–14 hrs

420i / 430i (LCI)B48B20£1,500–£2,800£2,500–£4,500£4,000–£6,00010–14 hrs

435i (pre-LCI)N55B30M0£2,000–£3,500£3,500–£6,000£5,000–£7,50012–16 hrs

440i (LCI)B58B30M0£2,500–£4,500£4,000–£7,000£5,500–£8,50012–16 hrs

M4 / M4 Comp / M4 CS / M4 GTSS55B30£5,000–£8,000£8,000–£14,000£12,000–£18,00016–22 hrs

418d / 420d / 425d (pre-LCI)N47D20£1,200–£2,500£2,500–£4,500£3,500–£5,50010–14 hrs

418d / 420d / 425d (LCI)B47D20£1,500–£2,800£2,800–£5,000£4,000–£6,50010–14 hrs

430d / 435dN57D30£2,500–£4,500£4,000–£7,000£5,500–£8,50012–16 hrs

Diesel & Petrol Lineup

Diesel Variants

Petrol Variants

Scope note: All variants listed are F36-generation 4 Series Gran Coupé only (2014–2020). The M4 uses the S55 engine and is included for completeness.

Market Intelligence

Most Requested Engines (2025)

Most Requested Variants

Average Replacement Cost

Most Common Failures

Most Requested Engines (2025)

Most Requested Variants

Average Replacement Cost

Most Common Failures

Most Requested Engines (2025)

Most Requested Variants

Average Replacement Cost

Most Common Failures

Diesel & Petrol Lineup

Diesel Variants

Petrol Variants

Scope note: All variants listed are F36-generation 4 Series Gran Coupé only (2014–2020). The M4 uses the S55 engine and is included for completeness.

Market Intelligence

Most Requested Engines (2025)

Most Requested Variants

Average Replacement Cost

Most Common Failures

Most Requested Engines (2025)

Most Requested Variants

Average Replacement Cost

Most Common Failures

Most Requested Engines (2025)

Most Requested Variants

Average Replacement Cost

Most Common Failures

FAQ

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BMW 4 Series F36 Engines — The Complete UK Guide

BMW 4 Series F36 Engine Codes — The Complete Database

BMW 4 Series F36 — Overview

Best & Worst Engines

BMW 4 Series F36 Ownership Economics

Common Problems

F36Engine Replacement Costs -By Engine and Condition

Diesel & Petrol Lineup

Market Intelligence

Diesel & Petrol Lineup

Market Intelligence

FAQ

Why UK BMW 4 Series F36 OwnersTrust bmwengines.uk

BMW 4 Series F36
Ownership Economics

F36
Engine Replacement Costs -By Engine and Condition

Why UK BMW 4 Series F36 Owners
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