Mercedes A Class M282/OM607/M260 Engine SolutionsUK Specialists

A replacement engine for a Mercedes-Benz A Class typically costs between £1,200 and £15,000 depending on the engine code, generation and condition. Used units start from £800-£2,500, rebuilt from £1,800-£5,500, and AMG engines from £8,000-£15,000.

• Used A180d (OM607) engines: £800-£1,500 depending on mileage
• Rebuilt M270 petrol units (A180/A200): £1,600-£3,200 supply only
• Rebuilt OM651 diesel units (A200 CDI/A220 CDI): £2,500-£4,800
• A45 AMG M133 rebuilt engines: £8,000-£12,000 from specialists
• Labour for supply & fit adds £400-£800 to any engine price

The M270 petrol (2012-2018 A180/A200/A250) and OM651 diesel (2012-2018 A180 CDI/A200 CDI/A220 CDI) engines are most known for timing chain tensioner failure. The chain sits at the rear of the engine, making replacement labour-intensive.

• M270 timing chain rattle typically appears between 80,000-150,000 miles
• OM651 rear-mounted chain requires gearbox removal for replacement
• Preventative chain replacement costs £1,400-£2,200 at a specialist
• Catastrophic chain failure causes bent valves - replacement engine needed
• Post-2018 M260/M282 and OM654 engines have improved chain designs

The OM651 is generally robust but has two well-documented weak points: EGR cooler cracking and timing chain tensioner failure. Post-2014 models received updated components that improved reliability, but preventative maintenance remains essential.

• EGR cooler cracks cause coolant loss and white smoke from exhaust
• HPFP failure on early OM651 units documented in TSB 07.01.15
• Post-2014 models include fixes for pre-2014 common flaws
• Regular oil changes every 10,000 miles minimise chain wear
• Many specialists offer upgraded EGR coolers with reinforced brazing

The M270 1.6L petrol (2012-2018 A180/A200) is widely considered the safest A-Class engine for used buyers. It has no AdBlue system, fewer emissions components than diesels, and timing chain issues are predictable and repairable before failure.

• M270 petrol avoids DPF, AdBlue and EGR cooler failure risks of diesels
• A200 petrol returns 48.7mpg - competitive with diesel for mixed driving
• OM607 diesel (A180d) is Renault-sourced and timing belt needs 80k-100k changes
• Post-2018 M282 petrol co-developed with Renault - generally reliable
• Avoid early OM651 diesels (2012-2014) with unresolved HPFP issues

A well-maintained A-Class petrol engine typically lasts 150,000-200,000 miles, while diesels regularly exceed 200,000-250,000 miles. The OM651 diesel in particular is capable of 300,000+ miles when serviced properly and timing chain issues are addressed proactively.

• M270 petrol: 150k-200k miles with regular oil changes
• OM651 diesel: 200k-300k miles - timing chain is the limiting factor
• OM654 diesel (2018+): Too new for full data, but build quality is excellent
• M282 petrol (2018+): 150k+ miles expected, HPFP is weak point
• Critical factors: Oil changes every 10k miles, not ignoring warning signs

Power loss on M270 engines is most commonly caused by timing chain stretch (causing cam timing drift), HPFP failure, or boost pressure sensor issues. A 2014 A200 owner on MBClub reported struggling past 70mph with no fault codes - intermittent boost sensor faults are notoriously hard to diagnose.

• Stretched timing chain allows camshaft timing to drift - reduces power
• HPFP failure causes misfires and limp mode without warning codes
• Boost pressure sensor faults can be intermittent and code-free
• Camshaft adjuster solenoid failure also causes power loss
• Diagnostic with Mercedes STAR system is essential for accurate fault finding

The A250e PHEV (M282 petrol + electric motor) has no recurrent reported failures according to European reliability studies. The 1.3L petrol unit is proven, and the electric motor integrated into the gearbox has been reliable. Battery degradation over time is the main long-term consideration.

• No chronic failures reported on the hybrid system as of 2024
• Electric-only range of 44 miles (WLTP) - battery health check recommended
• HV battery replacement is expensive (£3,000-£5,000) if out of warranty
• High-voltage system requires EV-trained specialist for engine work
• Cooling system leaks reported on some early electric motor units

Repair if the issue is timing chain or EGR cooler caught early. Replace if the engine has suffered timing chain snap (bent valves), HPFP failure that sent metal through the fuel system, or piston ring failure on AMG models. For A-Class cars worth under £3,000, a used engine swap often beats major repairs.

• Preventative timing chain replacement (£1,400-£2,200) beats engine replacement (£2,500-£5,500)
• EGR cooler replacement (£500-£900) prevents hydrolock damage
• HPFP metal contamination requires full engine replacement - flushing won't guarantee safety
• On W168/W169 worth £1k-£3k, used engine + fitting is most economical
• A45 AMG M133 rebuild (£8k-£12k) - compare against vehicle value

The OM651 (2012-2018) suffers EGR cooler cracking, timing chain tensioner wear, and HPFP failure. The OM654 (2018+) has AdBlue crystallisation and NOx sensor failures. The OM607 (A180d) has a timing belt needing replacement every 80,000-100,000 miles and injector seal leaks.

• OM651 EGR cooler cracks between 60k-100k miles - coolant loss, white smoke
• OM654 AdBlue system faults trigger countdown-to-no-start messages
• OM607 timing belt is an interference engine - failure means catastrophic damage
• DPF blockage common on all diesels used for short journeys only
• Post-2014 OM651 units have improved HPFP and chain tensioner designs

Your A-Class engine code is in the vehicle service booklet, on a sticker in the driver's door shut, or stamped on the engine block. You can also enter your registration number into our tool above for instant identification. Common A-Class codes include M270, M282, OM651, OM654 and OM607.

• Check service booklet or driver's door sill sticker for "M" or "OM" code
• Engine block stamp visible near cylinder head or oil filter housing
• VIN decoder tools can identify original factory engine code
• A180/A200 petrol 2012-2018: M270
• A180/A200 petrol 2018+: M282
• A180d 2012+: OM607 / A200d/A220d 2018+: OM654 / A200 CDI 2012-2018: OM651