How much does a BMW 8 Series E31 engine replacement cost in the UK?

A reconditioned E31 engine typically costs £3,000–£14,000 supply only [BMW-QUOTE], depending on engine -the M60 V8 sits at £3,000–£5,500, while the S70 V12 in the 850CSi can reach £14,000. Fitting adds £650–£1,500 depending on engine and specialist location.

Which BMW 8 Series E31 engine is the most reliable?

The M62B44 V8 is considered the most reliable E31 engine -improved over the M60 with better engine management and no Nikasil lining concerns. The M73B54 V12 is also highly reliable for a V12, with better engine management than the M70 [PROVISIONAL -pending dedicated Engine Page].

What are the common problems with the BMW 8 Series E31?

Cooling system failure is the most common issue across all E31 engines -overheating can cause catastrophic damage. The M60 V8 can suffer from Nikasil cylinder lining wear. The M70 V12 suffers from distributor cap and rotor failure. Fuel system issues are common on all ageing E31s.

Is the BMW 8 Series E31 reliable?

For a 30+ year-old classic car, the E31 is reasonably reliable -but it requires careful maintenance and specialist knowledge. The V8s are generally more affordable to maintain than the V12s. The M62 and M73 are the most reliable engine families. Buy a well-maintained example and budget for regular specialist servicing.

Which BMW 8 Series E31 engine should I avoid?

No engine is a hard avoid, but the pre-1995 M60 V8 requires very careful consideration -Nikasil cylinder lining wear is well-documented and a full replacement costs £4,500–£7,500 [BMW-QUOTE]. The M70 V12 is also high-risk without documented distributor and fuel system maintenance.

How do I know if my E31 engine needs replacing?

On M60 V8s, increased oil consumption or loss of power may indicate Nikasil lining wear -get a compression test immediately. On M70 V12s, misfires or rough running may indicate distributor cap or rotor failure. On any E31, sudden overheating is critical -stop driving immediately.

Is it worth replacing a BMW 8 Series E31 engine, or should I scrap the car?

Depends on the car's value. Against a well-kept £20,000 E31, a £5,000–£8,000 M70 recon is 25–40% -safe. Against a tired £10,000 example, the same recon is 50–80% -borderline. Our 70% BMW scrap threshold is the line [BMW-QUOTE]. For 850CSi cars, even the most expensive replacement is viable.

How long do BMW 8 Series E31 engines last?

The M60 and M62 V8s can exceed 150,000 miles with proper servicing -cooling system maintenance is the key to longevity. The M70 and M73 V12s are also capable of high mileages, but require more regular specialist attention. All E31s are now 25+ years old -condition and history matter more than mileage.

What is the difference between the 840Ci, 850i, 850Ci and 850CSi?

The 840Ci is the V8 model -M60 (1993–1995) or M62 (1995–1999). The 850i (1990–1994) uses the M70 5.0-litre V12. The 850Ci (1994–1999) uses the M73 5.4-litre V12. The 850CSi (1992–1996) uses the S70 5.6-litre V12 and is the only E31 offered exclusively with a 6-speed manual.

How do I find my BMW 8 Series E31 engine code?

Listed on the VIN plate and vehicle documentation; the engine code is also stamped on the engine block. Tell us your variant and production year, and we'll identify it -20+ vetted BMW specialists will confirm it for free.

E31 Engine Replacement Cost UK -Compare Quotes

Name: BMW 8 Series E31 UK Engine Enquiry Data 2025
Creator: BMWEngines.uk

BMW 8 Series E31 Engine Codes -The Complete Database

Every engine fitted to the E31 8 Series -spanning the M60 and M62 V8s, and the M70, M73 and S70 V12s that defined BMW's flagship grand tourer.

Engine CodeFamilyFuelDisplacementPowerYears (E31)Variants (badges)Reliability2025 EnquiriesAvg. Recon Cost

M60B40M60Petrol4.0L (3982cc)282–286 bhp1993–1995840Ci★★★★☆ [PROVISIONAL -pending dedicated Engine Page]-(pattern data)£3,000–£5,500 [BMW-QUOTE]

M62B44M62Petrol4.4L (4398cc)282–286 bhp1995–1999840Ci★★★★☆ [PROVISIONAL -pending dedicated Engine Page]-(pattern data)£3,200–£5,800 [BMW-QUOTE]

M70B50M70Petrol5.0L (4988cc)296–300 bhp1990–1994850i, 850Ci★★★☆☆ [PROVISIONAL -pending dedicated Engine Page]-(pattern data)£5,000–£8,000 [BMW-QUOTE]

M73B54M73Petrol5.4L (5379cc)322–326 bhp1994–1999850Ci★★★★☆ [PROVISIONAL -pending dedicated Engine Page]-(pattern data)£5,500–£9,000 [BMW-QUOTE]

S70B56S70Petrol5.6L (5576cc)375–380 bhp1992–1996850CSi★★★★☆ [PROVISIONAL -pending dedicated Engine Page]-(pattern data)£8,000–£14,000 [BMW-QUOTE]

Engine CodeFuelPowerYearsReliabilityEnquiriesAvg. Recon Cost

M60B40M60Petrol282–286 bhp1993–1995★★★★☆ [PROVISIONAL -pending dedicated Engine Page]-(pattern data)£3,000–£5,500 [BMW-QUOTE]

M62B44M62Petrol282–286 bhp1995–1999★★★★☆ [PROVISIONAL -pending dedicated Engine Page]-(pattern data)£3,200–£5,800 [BMW-QUOTE]

M70B50M70Petrol296–300 bhp1990–1994★★★☆☆ [PROVISIONAL -pending dedicated Engine Page]-(pattern data)£5,000–£8,000 [BMW-QUOTE]

M73B54M73Petrol322–326 bhp1994–1999★★★★☆ [PROVISIONAL -pending dedicated Engine Page]-(pattern data)£5,500–£9,000 [BMW-QUOTE]

S70B56S70Petrol375–380 bhp1992–1996★★★★☆ [PROVISIONAL -pending dedicated Engine Page]-(pattern data)£8,000–£14,000 [BMW-QUOTE]

Overview

BMW 8 Series E31 -Overview

The E31 is the first generation of the BMW 8 Series, unveiled at the 1989 Frankfurt Motor Show.

Production began in February 1990 and continued until May 1999. Designed as BMW's flagship grand tourer, the E31 was powered by a range of naturally aspirated V8 and V12 engines -a deliberate move away from the inline-six engines that had powered BMW's coupes for decades. The range initially launched with the M70-powered 850i V12, followed by the V8-powered 840Ci in 1993. A significant mid-life update brought the M73 5.4-litre V12 and M62 4.4-litre V8, while the S70-powered 850CSi remained the range-topping performance variant until production ended in 1996.

Key Facts

Platform

BMW E31 (Z1-based chassis)

Predecessor

E24 6 Series (not direct successor)

Successor

G15 8 Series (2018)

Sibling body styles

None (single 2-door coupé body style)

Market Intelligence

The E31 8 Series generated 120+ real UK engine enquiries in 2025 [BMW-VERIFIED], concentrated on the V8 840Ci and V12 850Ci as classic car buyers seek BMW's flagship grand tourer.

BMW 8 Series E31 -Overview

The E31 is the first generation of the BMW 8 Series, unveiled at the 1989 Frankfurt Motor Show.

Production began in February 1990 and continued until May 1999. Designed as BMW's flagship grand tourer, the E31 was powered by a range of naturally aspirated V8 and V12 engines -a deliberate move away from the inline-six engines that had powered BMW's coupes for decades. The range initially launched with the M70-powered 850i V12, followed by the V8-powered 840Ci in 1993. A significant mid-life update brought the M73 5.4-litre V12 and M62 4.4-litre V8, while the S70-powered 850CSi remained the range-topping performance variant until production ended in 1996.

Key Facts

Platform

BMW E31 (Z1-based chassis)

Predecessor

E24 6 Series (not direct successor)

Successor

G15 8 Series (2018)

Sibling body styles

None (single 2-door coupé body style)

Market Intelligence

The E31 8 Series generated 120+ real UK engine enquiries in 2025 [BMW-VERIFIED], concentrated on the V8 840Ci and V12 850Ci as classic car buyers seek BMW's flagship grand tourer.

Best & Worst Engines

Highest Risk

M70B50 (850i, 5.0L V12, 296 bhp)

“The M70 is a robust, over-engineered unit but age has taken its toll -distributor cap and rotor issues, fuel system problems, and cooling system failures are common on 30+ year-old examples. The early engine management system is less sophisticated than the M73's.”

Who it's for: buyers on a budget who are willing to invest in maintenance.

Most Expensive Failure

S70B56 (850CSi, 5.6L V12, 375–380 bhp)

“The S70 is the most expensive engine to maintain and replace in the E31 range -specialist parts are scarce, and a full rebuild can exceed £14,000. The 850CSi is a future classic, but it comes with six-figure maintenance expectations.”

Who it's for: collectors with deep pockets and specialist support.

Best Value

M60B40 (840Ci, 4.0L V8, 282 bhp)

“The M60-powered 840Ci is the most affordable entry point to E31 ownership -V8 running costs are significantly lower than the V12s, and the M60 is a proven engine (though check for Nikasil lining issues on early cars). It offers 90% of the 850i experience at a fraction of the price.”

Who it's for: buyers who want E31 ownership without V12 running costs.

Most Overlooked

M73B54 (850Ci, 5.4L V12, 322 bhp)

“The M73 is often overshadowed by the S70 -but it's the smart V12 buy. More power than the M70 (322 bhp vs 296), better engine management (Siemens OBD II), and significantly more reliable than its predecessor. It's the V12 to buy if you can't stretch to an 850CSi.”

Who it's for: buyers who want V12 refinement with modern(ish) engine management.

Highest Risk

M70B50 (850i, 5.0L V12, 296 bhp)

“The M70 is a robust, over-engineered unit but age has taken its toll -distributor cap and rotor issues, fuel system problems, and cooling system failures are common on 30+ year-old examples. The early engine management system is less sophisticated than the M73's.”

Who it's for: buyers on a budget who are willing to invest in maintenance.

Most Expensive Failure

S70B56 (850CSi, 5.6L V12, 375–380 bhp)

“The S70 is the most expensive engine to maintain and replace in the E31 range -specialist parts are scarce, and a full rebuild can exceed £14,000. The 850CSi is a future classic, but it comes with six-figure maintenance expectations.”

Who it's for: collectors with deep pockets and specialist support.

Best Value

M60B40 (840Ci, 4.0L V8, 282 bhp)

“The M60-powered 840Ci is the most affordable entry point to E31 ownership -V8 running costs are significantly lower than the V12s, and the M60 is a proven engine (though check for Nikasil lining issues on early cars). It offers 90% of the 850i experience at a fraction of the price.”

Who it's for: buyers who want E31 ownership without V12 running costs.

Most Overlooked

M73B54 (850Ci, 5.4L V12, 322 bhp)

“The M73 is often overshadowed by the S70 -but it's the smart V12 buy. More power than the M70 (322 bhp vs 296), better engine management (Siemens OBD II), and significantly more reliable than its predecessor. It's the V12 to buy if you can't stretch to an 850CSi.”

Who it's for: buyers who want V12 refinement with modern(ish) engine management.

BMW 8 Series E31 -Ownership Economics

EngineTypical MileageCommon Major FailureRepair Cost (Specialist)Replacement Cost (Recon)Ownership Verdict

M60B40 (4.0 V8)60k–100kNikasil lining (early), water pump, radiator£800–£2,500£3,000–£5,500

Solid Choice -check Nikasil history.

M62B44 (4.4 V8)80k–120kWater pump, timing chain guides, VANOS£800–£2,500£3,200–£5,800

Best V8 -improved over M60.

M70B50 (5.0 V12)60k–100kDistributor caps, rotors, fuel system, cooling£1,000–£3,000£5,000–£8,000

High Maintenance -over-engineered but ageing.

M73B54 (5.4 V12)80k–120kCooling system, ignition coils, fuel injectors£1,000–£2,500£5,500–£9,000

Best V12 -more reliable than M70.

S70B56 (5.6 V12)30k–60kRod bearings, camshaft wear, specialist parts£2,000–£5,000£8,000–£14,000

Ultimate V12 -collectable, costly to maintain.

EngineTypical MileageCommon Major FailureRepair Cost (Specialist)Replacement Cost (Recon)Ownership Verdict

M60B40 (4.0 V8)60k–100kNikasil lining (early), water pump, radiator£800–£2,500£3,000–£5,500

Solid Choice -check Nikasil history.

M62B44 (4.4 V8)80k–120kWater pump, timing chain guides, VANOS£800–£2,500£3,200–£5,800

Best V8 -improved over M60.

M70B50 (5.0 V12)60k–100kDistributor caps, rotors, fuel system, cooling£1,000–£3,000£5,000–£8,000

High Maintenance -over-engineered but ageing.

M73B54 (5.4 V12)80k–120kCooling system, ignition coils, fuel injectors£1,000–£2,500£5,500–£9,000

Best V12 -more reliable than M70.

S70B56 (5.6 V12)30k–60kRod bearings, camshaft wear, specialist parts£2,000–£5,000£8,000–£14,000

Ultimate V12 -collectable, costly to maintain.

The E31 rule

A £5,000–£8,000 M70 recon against a £8,000–£25,000 E31 sits at 20–100% of the car's value【BMW-QUOTE】. On a sub-£12,000 example, that brushes our 70% BMW threshold -we'll honestly tell you to walk away. Against a well-kept £20,000+ example, the same recon drops to 25–40% -a repair decision, not a financial one. Value the car first. For 850CSi cars (£30,000–£60,000+), even the most expensive S70 replacement is viable given collector values.

Key Takeaways

Which E31 Costs Least To Own?
M60/M62 840Ci -V8 running costs are significantly lower than the V12s.
Which E31 Costs Most To Own?
S70 850CSi -parts scarcity and V12 complexity make this the most expensive E31 to maintain.
Which E31 Is Best Value?
M73 850Ci (post-1994) -V12 refinement with more reliable engine management than the M70.

Common Problems

01

M60

V8 Nikasil Cylinder Lining Wear

Affected models:

E31 840Ci (1993–1995, M60B40 engine).

Typical failure mileage:

60,000–100,000 miles.

Root cause:

Early M60 V8s used Nikasil (nickel-silicon carbide) cylinder linings which could degrade when exposed to high-sulphur fuels. This led to loss of compression, increased oil consumption, and eventual engine failure. BMW issued a recall and replaced affected engines with Alusil-lined units.

Tiered Cost Table

Preventative (Repair)

Dealer

Specialist

£2,000–£4,000 (compression test + cylinder inspection)

£1,000–£2,000 (compression test + cylinder inspection)

Cylinder compression test, borescope inspection

Catastrophic (Replacement)

Dealer

Specialist

£6,000–£9,000

£4,500–£7,500

Full M60 engine replacement or rebuild

Our Recommendation

If you're buying an M60-powered 840Ci (1993–1995), get a compression test and borescope inspection before committing -£1,000–£2,000 now is far cheaper than the £4,500+ engine replacement that follows if the Nikasil linings have failed. Check the vehicle's service history for evidence of recall work.

Compare M60 engine prices for your 840Ci

02

M70

V12 Distributor Cap & Rotor Failure

Affected models:

E31 850i (1990–1994, M70B50 engine).

Typical failure mileage:

40,000–80,000 miles (age-related).

Root cause:

The M70 V12 uses two distributor caps and rotors -one for each bank of cylinders. These components degrade with age and heat, leading to misfires, rough running, and reduced performance. The caps and rotors are becoming increasingly difficult to source.

Tiered Cost Table

Preventative (Repair)

Dealer

Specialist

£800–£1,500

£500–£1,000

Distributor cap and rotor replacement

Catastrophic (Replacement)

Dealer

Specialist

£5,000–£8,000

£4,500–£7,000

Full M70 engine replacement if misfire caused damage

Our Recommendation

Replace the distributor caps and rotors every 40,000 miles or 5 years -a £500–£1,000 specialist job is cheap insurance against a £4,500+ engine replacement that follows if misfire damage occurs. Keep a spare set if you plan to keep the car long-term -these parts are getting harder to find.

Compare M70 engine parts for your 850i

03

E31

Cooling System Failure (All Engines)

Affected models:

All E31 models (M60, M62, M70, M73, S70).

E31 Cooling System Failure (All Engines)

Typical failure mileage:

50,000–100,000 miles.

Root cause:

The E31's cooling system uses plastic components that become brittle with age -water pumps, radiators, expansion tanks and hoses are all potential failure points. Overheating can cause catastrophic engine damage on both V8 and V12 engines.

Tiered Cost Table

Preventative (Repair)

Dealer

Specialist

£1,000–£2,000

£600–£1,500

Water pump, thermostat, radiator, hoses replacement

Catastrophic (Replacement)

Dealer

Specialist

£5,000–£9,000

£4,500–£8,000

Full engine replacement if overheating caused damage

Our Recommendation

Replace the entire cooling system (water pump, thermostat, radiator, expansion tank, hoses) as preventative maintenance at 60,000 miles or 10 years -a £600–£1,500 specialist job is dramatically cheaper than the £4,500+ engine replacement that follows an overheating event. This is the single most important maintenance item on any E31.

Compare E31 cooling system parts

04

E31

Fuel System & Injector Issues (All Engines)

Affected models:

All E31 models, particularly V12s (M70, M73, S70).

E31 Fuel System & Injector Issues (All Engines)

Typical failure mileage:

50,000–100,000 miles (age-related).

Root cause:

The E31's fuel system is complex -the V12s have two separate fuel rails and two fuel pumps. Fuel injectors can become clogged or fail with age, leading to rough running, poor economy, and potential engine damage. The fuel pumps are also a known weak point.

Tiered Cost Table

Preventative (Repair)

Dealer

Specialist

£1,000–£2,000

£500–£1,500

Fuel injector cleaning/replacement, fuel pump replacement

Catastrophic (Replacement)

Dealer

Specialist

£5,000–£9,000

£4,500–£8,000

Full engine replacement if fuel starvation caused damage

Our Recommendation

Have the fuel injectors cleaned or replaced at 60,000 miles -a £500–£1,500 specialist job is far cheaper than the £4,500+ engine replacement that follows if fuel starvation causes a lean-running failure. On V12 cars, budget for two fuel pumps if they haven't been replaced.

Compare E31 fuel system parts

E31 Engine Replacement Costs -By Engine and Condition

VariantEngine CodeUsed (Supply)Reconditioned (Supply)Rebuilt (Supply)Labour Hours

840Ci (4.0 V8, 1993–1995)M60B40£1,500–£3,000£3,000–£5,500£4,500–£7,50012–16 hrs

840Ci (4.4 V8, 1995–1999)M62B44£1,600–£3,200£3,200–£5,800£4,800–£8,00012–16 hrs

850i / 850Ci (5.0 V12, 1990–1994)M70B50£2,500–£4,500£5,000–£8,000£7,000–£10,00016–22 hrs

850Ci (5.4 V12, 1994–1999)M73B54£2,800–£5,000£5,500–£9,000£7,500–£11,00016–22 hrs

850CSi (5.6 V12, 1992–1996)S70B56£4,500–£8,000£8,000–£14,000£10,000–£18,00018–24 hrs

No Generation variance from the EM_Proprietary_Data baseline figures -E31 is a unique generation with no direct successor cost comparison. Costs are derived from specialist market data and tagged [BMW-QUOTE].

Core Variants

Diesel & Petrol Lineup

Petrol Variants

840Ci850CSi850i / 850Ci

Scope note: All variants listed are E31 8 Series only. The 840Ci switched from the M60B40 (1993–1995) to the M62B44 (1995–1999). The 850i (1990–1994) used the M70B50; the 850Ci (1994–1999) used the M73B54. The 850CSi (1992–1996) used the S70B56 and was the only E31 offered exclusively with a 6-speed manual transmission. The 850i became the 850Ci around the introduction of the 850CSi -both M70 and M73-engined cars were sold as 850Ci for a period in 1994.

Diesel & Petrol Lineup

Petrol Variants

840Ci850CSi850i / 850Ci

Scope note: All variants listed are E31 8 Series only. The 840Ci switched from the M60B40 (1993–1995) to the M62B44 (1995–1999). The 850i (1990–1994) used the M70B50; the 850Ci (1994–1999) used the M73B54. The 850CSi (1992–1996) used the S70B56 and was the only E31 offered exclusively with a 6-speed manual transmission. The 850i became the 850Ci around the introduction of the 850CSi -both M70 and M73-engined cars were sold as 850Ci for a period in 1994.

Market Intelligence

Most Requested E90 Engines (2025)

1.1. M62B44 (largest share of V8 enquiries)
2.2. M73B54
3.3. M70B50

Most Requested E90 Variants

1.1. 840Ci
2.2. 850Ci
3.3. 850CSi

Average E90 Replacement Cost

£5,500 reconditioned, supply only [BMW-QUOTE]

Most Common E90 Failures

1.1. Cooling system failure
2.2. M60 Nikasil lining wear
3.3. M70 distributor cap/rotor failure

Live Feed

VehicleLocationIssueEnquiries

BMW 8 Series

E31 840Ci

London

Cooling system inspection

3

enquiries

BMW 8 Series

E31 850Ci

Surrey

Pre-purchase inspection

2

enquiries

BMW 8 Series

E31 850CSi

Oxford

Rod bearing inspection

1

enquiry

Updated Monthly

FAQ

BMW 3 Series E90 rear three-quarter view

Why UK BMW 8 Series E31 Owners Trust BMWEngines.uk

Trusted E31 Engine Suppliers
every garage and engine rebuilder in our network is vetted, rated and reviewed by real 8 Series owners, as part of the Engine Finders network.
Compare E31 Engine Replacement Companies
see prices, warranty terms and supply & fit options side-by-side before you commit.
UK Engine Replacement Services for E31
covering every variant from 840Ci to 850CSi, with supply-only or full supply & fit available nationwide.

Find the best BMW 8 Series E31 engine replacement UK drivers rely on. Compare real prices from trusted specialists on EnginesMarket today and keep your classic on the road.

Compare BMW 8 Series E31 Engine Prices on EnginesMarket

Why UK BMW 8 Series E31 Owners Trust BMWEngines.uk

Trusted E31 Engine Suppliers
every garage and engine rebuilder in our network is vetted, rated and reviewed by real 8 Series owners, as part of the Engine Finders network.
Compare E31 Engine Replacement Companies
see prices, warranty terms and supply & fit options side-by-side before you commit.
UK Engine Replacement Services for E31
covering every variant from 840Ci to 850CSi, with supply-only or full supply & fit available nationwide.

Find the best BMW 8 Series E31 engine replacement UK drivers rely on. Compare real prices from trusted specialists on EnginesMarket today and keep your classic on the road.

Compare BMW 8 Series E31 Engine Prices on EnginesMarket

BMW 8 Series E31 Engines -The Complete UK Guide

BMW 8 Series E31 Engine Codes -The Complete Database

BMW 8 Series E31 -Overview

BMW 8 Series E31 -Overview

Best &amp; Worst Engines

BMW 8 Series E31 -Ownership Economics

Common Problems

E31 Engine Replacement Costs -By Engine and Condition

Diesel &amp; Petrol Lineup

Diesel &amp; Petrol Lineup

Market Intelligence

FAQ

Why UK BMW 8 Series E31 Owners Trust BMWEngines.uk

Why UK BMW 8 Series E31 Owners Trust BMWEngines.uk

Best & Worst Engines

Diesel & Petrol Lineup

Diesel & Petrol Lineup