BMW 3 Series M340i Engine ReplacementCompare Prices & Get Quotes

A BMW 3 Series M340i engine replacement typically costs £4,500-£6,500 for a rebuilt unit supply-only, or £5,500-£8,500 fitted by a specialist. Used engines start from around £2,500-£4,000, while reconditioned units range from £4,000 to £5,500.

• Prices reflect the B58's performance pedigree and relative scarcity
• Rebuilt engines carry a 12-month unlimited-mileage warranty
• Supply & fit adds £500-£1,500 in labour depending on the workshop

The most common symptoms of high-pressure fuel pump failure include long cranking times during startup (especially in cold weather), a noticeable loss of power during acceleration, engine stalling, and the car entering limp-mode with a warning light.

• Long cranking is the #1 early symptom - don't ignore it
• HPFP failure can send metal debris into the fuel system, destroying injectors
• Replacing a failing HPFP (£800-£1,400) is far cheaper than a full engine replacement

Yes - the M340i retains strong values (typically £25,000-£45,000), so a full engine replacement at £4,500-£6,500 represents a relatively small proportion of the vehicle's worth (10-25%). For a well-maintained example, a rebuilt engine with warranty is almost always a justifiable investment.

• The M340i's high retained value makes replacement economically viable
• A rebuilt engine with upgraded components can exceed original reliability
• For cars with significant body or interior damage, evaluate overall condition

The M340i uses the B58B30O1 - a specific high-output version of BMW's modular B58 engine family. It features 374hp and 500Nm of torque, a twin-scroll turbocharger, and has been tuned specifically for M Performance models. The engine shares its basic architecture with B58 engines in the 340i, 540i and X3 M40i, but features different ECU calibration, and in some cases, different internals.

• B58B30O1: 374hp, fitted to M340i, Z4 M40i, and later Toyota Supra models
• Other B58 variants produce between 335hp and 382hp depending on the application

A typical BMW 3 Series M340i engine replacement takes 2-4 days for a specialist workshop, assuming the replacement engine is already in stock. The B58 is a complex engine, and xDrive models require additional labour.

• Allow 2-4 days for supply & fit through a specialist
• Supply-only engines are typically dispatched within 1-2 working days
• xDrive models add approximately 2-4 hours of labour

Every rebuilt and reconditioned BMW 3 Series M340i engine supplied through EnginesMarket carries a minimum 12-month unlimited-mileage warranty. Used engines typically come with a shorter warranty (30-90 days) depending on the supplier - always confirm exact terms before purchasing.

• Rebuilt: 12 months / unlimited mileage minimum
• Reconditioned: typically 6-12 months
• Used: 30-90 days, supplier-dependent