Mercedes-Benz CLC 200 CDI / 220 CDI Engine Replacement Compare Prices & Get Quotes

A replacement OM646 engine for a CLC 200 CDI or 220 CDI typically costs between £800 and £3,200 depending on condition and engine code. Used units start from £800-£1,600, reconditioned from £1,400-£2,800, and fully rebuilt from £1,800-£3,200. Labour for supply & fit adds £500-£900. A replacement OM646.963 engine costs on average £1,246 in good condition, with reconditioned units costing up to £1,495.

• Used OM646.981 (CLC 200 CDI): £800-£1,400
• Rebuilt OM646.980 (CLC 220 CDI): £1,800-£3,200

Swirl flap failure is the #1 diesel killer in OM646 engines. Plastic swirl flaps in the inlet manifold can break and be ingested into cylinders, causing catastrophic piston, valve, and cylinder head damage. Symptoms include loss of power, limp mode, a hissing intake sound, and fault codes P2004 or P2006. The permanent fix is swirl flap removal and blanking (£400-£800) - not replacement with another plastic manifold.

• Affects both CLC 200 CDI and 220 CDI (OM646.981 and OM646.980)
• Flap removal and blanking is the permanent solution
• Ignoring fault codes can lead to £3,000+ engine replacement

Both use the OM646 2.1-litre four-cylinder turbodiesel, but with different power outputs. The CLC 200 CDI uses the OM646.981 producing 122 hp (90 kW) and 270 Nm torque. The CLC 220 CDI uses the OM646.980 producing 150 hp (110 kW) and 330 Nm torque. Both share the same basic architecture, common-rail injection, and variable geometry turbocharger.

• OM646.981 (CLC 200 CDI): 122 hp, 270 Nm
• OM646.980 (CLC 220 CDI): 150 hp, 330 Nm
• Both share the same swirl flap, injector seal, and EGR weaknesses

It depends on the car's condition and mileage. A CLC 200 CDI or 220 CDI is typically worth £2,000-£5,000 - a rebuilt OM646 engine (£1,800-£3,200) can be a worthwhile investment if the car is in good condition. For lower-value examples, a targeted repair (swirl flap delete, injector seals) may be more economical than a full replacement.

• Vehicle worth £2,000-£3,500: targeted repair often more economical
• Vehicle worth £3,500+: rebuilt engine with warranty is viable
• Swirl flap delete: £400-£800 - the best preventative investment

Power loss in the CLC 200 CDI and 220 CDI is most commonly caused by EGR valve clogging from carbon deposits, turbocharger issues (sticking variable vanes), or swirl flap failure. Injector seal leakage can also cause compression loss and reduced performance. A diagnostic check with Mercedes STAR or compatible equipment is essential to identify the exact cause.

• EGR valve clogging - carbon deposits from short journeys
• Turbocharger vanes - sticking from carbon buildup
• Swirl flap failure - broken flaps reducing airflow

The OM646 is generally robust and capable of 200,000-400,000 miles with proper maintenance. However, it has well-documented weak points: swirl flap collapse (the #1 failure driver), injector seal leakage, and EGR valve clogging. Addressing swirl flaps preventatively with a delete kit is the single most important thing you can do to ensure long-term reliability.

• OM646 longevity: 200,000-400,000 miles with regular maintenance
• Swirl flap delete is essential preventative maintenance
• Regular oil changes (MB229.5 spec) are critical