Mercedes Benz GLK Class 320 CDI/350 CDI Engine ReplacementCompare Prices & Get Quotes

Short summary: A rebuilt OM642 engine for the GLK 320 CDI costs £3,800-£4,900 supply-only; a rebuilt OM642 engine for the GLK 350 CDI costs £4,000-£5,300 supply-only. Fitting adds £700-£1,300 depending on complexity - V6 work requires specialist knowledge.

• GLK 320 CDI (OM642.930): rebuilt unit £3,800-£4,900; used engine from £1,800
• GLK 350 CDI (OM642.832/835): rebuilt unit £4,000-£5,300; used engine from £2,000
• OM642 oil cooler seal replacement (labour only): £900-£1,400 at specialist
• OM642 EGR cooler + swirl flap replacement: £1,200-£1,900 at specialist

Short summary: A burnt-oil smell after highway driving or oil pooling in the V of the engine is the classic warning sign. The oil seals themselves are a £10 item; the labour to replace them is about £900 at a specialist. If ignored, coolant contamination leads to bearing washout and terminal engine seizure.

• Burnt-oil smell from the engine bay after highway driving
• Oil pooling in the valley between V6 cylinder banks
• Oil dripping onto the exhaust system
• If caught early, Viton seal replacement costs £900-£1,400 at specialist

Short summary: The OM642 V6 is a fundamentally strong and refined engine - the 3.0-litre V6 turbodiesel found across Mercedes' SUV and van range. It has one famous weak point: the oil cooler seals. With upgraded Viton seals fitted, these engines routinely exceed 150,000 miles.

• OM642 is fundamentally robust with proven durability
• Oil cooler seal degradation is the dominant failure - £10 part, £900 labour
• EGR cooler and swirl flap issues are secondary but manageable
• Turbo seals are notorious for causing major issues if leaks aren't addressed
• Well-maintained OM642 engines exceed 150,000 miles

Short summary: Properly maintained OM642 V6 engines routinely reach 150,000-200,000+ miles before major work is needed. With upgraded Viton oil cooler seals fitted, these engines demonstrate exceptional longevity.

• OM642 (320/350 CDI): 150,000-200,000+ miles with regular servicing
• Oil cooler seal replacement recommended from 80,000-130,000 miles
• Service interval is 10,000 miles or 12 months - use Mercedes-spec low-SAPS oil (MB 229.51/229.52)
• Late oil changes accelerate oil cooler seal degradation and turbo wear

Short summary: Yes, if the GLK is otherwise in good condition with no rust or major electrical or transmission faults. A rebuilt OM642 costs £3,800-£5,300 - 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 320/350 CDI values: £4,000-£12,000 depending on year, mileage and condition
• Rebuilt engine with upgraded Viton seals fixes original weak points
• Supply & fit typically £4,500-£6,600 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 OM642 V6 requires approximately 8.0 litres with filter.

• OM642 (320/350 CDI): MB 229.51/229.52 5W-30 low-SAPS - protects DPF and emissions systems
• Never use non-approved oil - can cause excessive soot buildup
• Change every 10,000 miles or 12 months - stretched intervals cause oil cooler seal degradation and turbo wear