BMW 8 Series 840Ci Engine Replacement Compare Prices & Get Quotes

A BMW 8 Series 840Ci engine replacement typically costs £1,200-£2,200 for a used M60B40 or M62B44 unit, £2,200-£3,800 for a reconditioned engine, and £3,000-£5,000 for a fully rebuilt engine with warranty. Supply & fit adds £650-£910 in specialist labour (10-14 hours).

• Used engines: lowest upfront cost, limited warranty
• Reconditioned: mid-range, some new parts fitted
• Rebuilt: highest cost, fully restored to factory spec with 12-month warranty

Common symptoms include a rattling or grinding noise from the front of the engine on cold startup, rough idle, and reduced performance. In advanced cases, the engine may misfire or show timing-related fault codes. If you hear a rattle, have the tensioner inspected immediately - a failed tensioner can allow the chain to slip, causing catastrophic engine damage.

• Rattling on startup: classic symptom
• Rough idle / misfires: chain slack affecting timing
• Engine damage: risk if ignored

With average values of £5,000-£15,000, a full rebuilt engine at £3,000-£5,000 represents 20-60% of the vehicle's value. For well-maintained examples worth £10,000+, a rebuilt engine can be a sound investment that preserves the car's value and extends its life by 100,000+ miles.

• Sub-£6,000 car: consider a used engine or targeted repair
• £6,000-£10,000 car: reconditioned engine is viable
• £10,000+ car: rebuilt engine with warranty makes strong financial sense

A typical BMW 8 Series 840Ci engine replacement takes 2-5 days for supply and fit at a specialist garage. The M60B40 and M62B44 are V8 engines with good engine bay access on the E31, but the job requires removing the front end and gearbox. Most specialists offer collection/delivery options nationwide.

• Same-day dispatch available for in-stock engines
• Fitting typically completed within 3-5 working days
• Collection/delivery options available across the UK

The 840Ci uses a V8 engine (4.0L M60B40 or 4.4L M62B44, 286hp), while the 850Ci uses a V12 engine (5.0L M70B50 or 5.4L M73B54, 326hp). The 840Ci offers better fuel economy and lower running costs, while the 850Ci delivers more power and the unique character of a V12. The 840Ci engine replacement cost is generally lower than the 850Ci's V12.

• 840Ci: V8, 4.0-4.4L, 286hp, 400-420Nm torque
• 850Ci: V12, 5.0-5.4L, 326hp, 490Nm torque
• 840Ci replacement cost: generally lower than 850Ci

The M60B40 and M62B44 V8s are generally robust engines, but age-related issues are now common. The M60B40 is known for timing chain tensioner wear and Nikasil cylinder lining issues on early cars. The M62B44 is prone to intake air leaks and oil leaks. Regular maintenance and early diagnosis of symptoms are key to longevity.

• M60B40: timing chain tensioner - inspect at 80,000 miles
• M62B44: intake air leaks - check regularly for rough idle
• Both: oil leaks - common from valve covers and main seals