Mercedes-Benz A-Class 180 CDI Engine Replacement Compare Prices & Get Quotes

A replacement engine for an A180 CDI typically costs between £600 and £4,800 depending on the engine code and condition. Used OM607 units start from £600-£1,500, reconditioned from £1,800-£3,200, and fully rebuilt OM651 engines from £2,500-£4,800. Labour for supply & fit adds £400-£800.

• Used OM640 (W169): £500-£1,200
• Rebuilt OM651 (W176, 2012-2014): £2,500-£4,800
• Rebuilt OM607 (W176, 2014-2018): £2,200-£3,800

On OM651-equipped A180 CDI models (2012-2014), the most common symptom is a rattling noise from the rear of the engine on cold start. Other signs include loss of power, engine misfires, and the engine management light illuminating. If you hear any unusual sounds, have the timing system inspected immediately - ignoring the rattle can lead to catastrophic engine failure.

• Cold-start rattle from the rear of the engine
• Loss of power and rough running
• Engine management light activation

It depends on the generation and condition. A W169 A180 CDI is typically worth £1,500-£4,000 - a full engine replacement often exceeds the car's value, making a used engine or targeted repair more economical. A W176 A180 CDI is worth £4,000-£12,000 - a rebuilt OM651 or OM607 engine (£2,200-£4,800) can be a worthwhile investment if you plan to keep the car. Always compare the cost of repair against the car's market value.

• W169 (2004-2012): used engine or targeted repair
• W176 (2012-2018): rebuilt engine with warranty is viable
• Vehicle worth over £6,000: replacement usually justifies the cost

The OM640 (W169) and OM651 (early W176) engines are known for their durability and can exceed 200,000-250,000 miles with proper maintenance. The OM607 (late W176) is also capable of high mileage, but its timing belt must be replaced every 80,000-100,000 miles - failure to do so is catastrophic. Regular oil changes (every 10,000 miles) and timely replacement of wear items are key to maximising engine life.

• OM640/OM651: 200,000+ miles achievable
• OM607: high-mileage capable but timing belt is critical
• Regular maintenance is essential for all variants

The OM651 is Mercedes' own 1.8-litre four-cylinder diesel with a rear-mounted timing chain, used in the W176 A180 CDI from 2012-2014. The OM607 is a Renault-sourced 1.5-litre diesel (K9K) with a timing belt, introduced in the 2014 facelift and used until 2018. Both produce 109 hp, but the OM651 has more torque (250 Nm vs 260 Nm). The OM607 is lighter and more fuel-efficient, but its timing belt requires regular replacement.

• OM651: 1.8L, timing chain, Mercedes-designed
• OM607: 1.5L, timing belt, Renault-sourced
• Both: 109 hp, but OM607 has slightly more torque

Power loss in the A180 CDI can be caused by several issues depending on the engine. On OM651 engines, timing chain stretch can cause cam timing drift, reducing power. On both OM651 and OM607, EGR valve clogging, DPF blockage, or turbocharger actuator failure are common culprits. On OM607, a failing timing belt can also cause timing drift. A diagnostic check with Mercedes STAR or compatible equipment is essential to identify the exact cause.

• Timing chain stretch (OM651) - power loss + rattling
• EGR valve / DPF clogging - common on all diesels
• Turbo actuator failure - especially on OM607