Mercedes Benz GLK Class 220 CDI/250 CDI Engine Replacement Compare Prices & Get Quotes

Short summary: A rebuilt OM651 engine for the GLK 220 CDI costs £2,400-£3,400 supply-only; a rebuilt OM651 engine for the GLK 250 CDI costs £2,800-£3,700 supply-only. Fitting adds £700-£1,300 depending on complexity.

• GLK 220 CDI (OM651.911/916): rebuilt unit £2,400-£3,400; used engine from £1,200
• GLK 250 CDI (OM651.912/921): rebuilt unit £2,800-£3,700; used engine from £1,500
• OM651 timing chain kit (labour only): £950-£1,500 at specialist
• OM651 EGR cooler replacement: £500-£750 at specialist

Short summary: A rattling noise on cold start is the classic warning sign on the OM651 engine. If ignored, it can lead to misfires, cam/crank correlation codes, and catastrophic engine damage if the chain jumps a tooth.

• Cold start rattle that disappears after oil pressure builds - earliest warning
• Check engine light with cam/crank correlation codes
• Metallic swarf in engine oil indicates chain guides wearing away
• Preventative tensioner replacement costs £350-550 - full chain kit £950-1,500

Short summary: The OM651 is fundamentally reliable - 200,000-300,000 km examples are common. However, it has predictable weak points: timing chain stretch from approximately 120,000 km, early Delphi injector failures, EGR clogging, and water pump leaks. All are manageable with the right maintenance schedule and proactive attention.

• Timing chain stretch is the single most critical failure point
• EGR cooler cracking affects all OM651-powered GLK 220/250 CDI variants
• Early Delphi piezo injectors prone to failure - later magnetic types more durable
• Well-maintained OM651 engines exceed 150,000 miles

Short summary: Properly maintained OM651 engines routinely reach 150,000-200,000+ miles (200,000-300,000 km) before major work is needed. With timely timing chain service and regular maintenance, these engines demonstrate exceptional longevity.

• OM651 (220/250 CDI): 150,000-200,000+ miles with regular servicing
• Timing chain inspection recommended from 75,000 miles (120,000 km)
• Service interval is 10,000 miles or 12 months - use Mercedes-spec low-SAPS oil
• Late oil changes accelerate timing chain wear and EGR clogging

Short summary: Yes, if the GLK is otherwise in good condition with no rust or major electrical faults. A rebuilt OM651 costs £2,400-£3,700 - comparable to or less than replacing a £4,000-£12,000 vehicle, especially when factoring in the cost of finding a comparable replacement SUV.

• GLK 220/250 CDI values: £4,000-£12,000 depending on year, mileage and condition
• Rebuilt engine with upgraded components fixes original weak points
• Supply & fit typically £3,200-£5,000 depending on engine code
• New engine includes 12-month unlimited mileage warranty

Short summary: Mercedes-Benz specifies low-SAPS oil meeting MB 229.51 or 229.52 - typically 5W-30. The OM651 requires approximately 6.5 litres with filter.

• OM651 (220/250 CDI): MB 229.51/229.52 5W-30 low-SAPS - protects DPF and emissions systems
• Never use non-approved oil - destroys timing chain tensioners and hydraulic lifters
• Change every 10,000 miles or 12 months - stretched intervals cause timing chain wear and EGR clogging