BMW B58B30O1 Engine - Replacement Cost, Problems & CompatibilityProblems & Compatibility

A reconditioned B58B30O1 supply-only typically costs between £3,800 and £6,000, with fitted prices ranging from £4,450 to £6,910 depending on labour rates and any additional parts required. Used units start from £2,000 supply-only, while full rebuilds run £5,000-£8,000. All figures are [EM-QUOTE] from independent UK specialists. Prices vary with mileage, service history, and whether the cooling system or PCV have been addressed. Supply-only excludes fitting; add 10-14 hours at £65-£91/hr for installation. Always compare multiple quotes - prices can vary by 20% between specialists.

• Prices vary with mileage, service history, and whether the cooling system or PCV have been addressed.
• Supply-only excludes fitting; add 10-14 hours at £65-£91/hr for installation.
• Always compare multiple quotes - prices can vary by 20% between specialists.

Coolant system leaks - specifically from the expansion tank, hoses, and electric water pump - are the most frequently reported issue on the B58 family. The integrated plastic fittings can become brittle with heat cycling, and the water pump has a high workload. Typical onset is 60,000-120,000 miles. Oil filter housing gasket leaks and PCV valve failure (requiring head cover replacement) are also common. Unlike earlier BMW turbocharged engines, timing chain wear is not a widespread concern on the B58. Catch cooling system issues early to avoid overheating and potential head gasket damage.

• Oil filter housing gasket leaks and PCV valve failure (requiring head cover replacement) are also common.
• Unlike earlier BMW turbocharged engines, timing chain wear is not a widespread concern on the B58.
• Catch cooling system issues early to avoid overheating and potential head gasket damage.

The B58B30O1 is fitted across BMW's G-generation range from 2019 onward. Models include the M340i (G20/G21), M440i (G22/G23), X3 M40i (G01), X4 M40i (G02), X5 xDrive40i (G05), X6 xDrive40i (G06), X7 xDrive40i (G07), Z4 M40i (G29), 7 Series 740i (G11/G12), 8 Series 840i (G14/G15/G16), and the 2 Series M240i (G42). It's also used in the Toyota GR Supra. The engine powers both rear- and all-wheel-drive variants across most models. Check your vehicle's V5C or VIN plate to confirm the exact engine code.

• The engine powers both rear- and all-wheel-drive variants across most models.
• Check your vehicle's V5C or VIN plate to confirm the exact engine code.
• Our compatibility table above lists every UK-fitment model and generation.

For most owners of an M340i, X3 M40i, or 4 Series, a reconditioned unit is the best balance - it addresses the known weaknesses (cooling system, PCV, gaskets) and comes with a 12-24 month warranty. Used units are cheaper but carry higher risk unless they have full documented history. Rebuilds are typically reserved for high-value hosts (X5, X7, 8 Series) or modified/track cars requiring upgraded internals. Used: from £2,000 - only with proof of cooling system maintenance and service history. Reconditioned: from £3,800 - the recommended choice for most road cars. Rebuilt: from £5,000 - ideal for high-value vehicles or performance builds.

• Used: from £2,000 - only with proof of cooling system maintenance and service history.
• Reconditioned: from £3,800 - the recommended choice for most road cars.
• Rebuilt: from £5,000 - ideal for high-value vehicles or performance builds.

The engine code is stamped on a machined pad on the engine block, visible from the driver's side of the engine bay. It also appears on the V5C registration document under 'Engine number' (e.g. B58B30O1xxxxxx). You can also use a BMW VIN decoder (available online) to extract the engine code from the vehicle's build sheet. Common confusion: B58B30M0 (326 hp), B58B30M1 (382 hp), and B58B30O0 (pre-TU) have different ECU calibrations and cooling/hardware differences. Fitting the wrong engine variant without corresponding ECU and component swaps will cause drivability issues.

• Common confusion: B58B30M0 (326 hp), B58B30M1 (382 hp), and B58B30O0 (pre-TU) have different ECU calibrations and cooling/hardware differences.
• Fitting the wrong engine variant without corresponding ECU and component swaps will cause drivability issues.
• Enter your reg above and we'll confirm your exact code for you.

With proper maintenance, a B58B30O1 is capable of 150,000-200,000+ miles without major internal issues. Many owners report trouble-free running beyond 120,000 miles when coolant system components and the PCV system are replaced proactively at the correct intervals. Key maintenance: replace water pump and thermostat at 80,000 miles; check oil filter housing gasket; replace cylinder head cover (PCV) if oil consumption increases. The engine is considered robust and is often modified beyond 500 hp with supporting mods. The rear-mounted timing chain is not a common failure point - unlike BMW's N47/N57 diesels.

• Key maintenance: replace water pump and thermostat at 80,000 miles; check oil filter housing gasket; replace cylinder head cover (PCV) if oil consumption increases.
• The engine is considered robust and is often modified beyond 500 hp with supporting mods.
• The rear-mounted timing chain is not a common failure point - unlike BMW's N47/N57 diesels.