320/350 CDI 3.0 V6 (OM642)
2008–2015 · diesel · 2987cc · 224hp
Engine codes: OM642
Reliability, common problems and owner reviews for the Mercedes Benz GLK 320/350 CDI 3.0 V6 (OM642). Check this before you buy used.
The 3.0 V6 CDI (OM642) is the smooth, effortless GLK diesel — the same robust six used across C/E-Class, ML and the Jeep Grand Cherokee, well-matched to the SUV. Budget for the OM642's signature niggles: the oil-cooler seals (in the V, under the intake) harden and leak, and the intake swirl-flap actuator fails. Plus EGR/DPF and high-mileage injection. With those addressed and good history it's a dependable, long-legged engine — the pick of the GLK range.
Same engine, other cars
This is the same physical engine (OM642) sold under different names across brands. Reliability is broadly shared — cross-check these:
- Mercedes-Benz Vito / Viano— 3.0 CDI V6 (OM642)224hp
- Jeep Grand Cherokee— 3.0 CRD V6 (OM642, Mercedes)218hp
- Mercedes-Benz M-Class (ML)— ML350 CDI 3.0 V6 (OM642)258hp
- Mercedes-Benz E-Class W211— E280 / E320 CDI 3.0 V6 (OM642)224hp
- Mercedes-Benz M-Class (ML)— ML280/320/350 CDI 3.0 V6 (OM642)224hp
- Mercedes-Benz C-Class W204— C320 / C350 CDI 3.0 V6 (OM642)224hp
Known Issues
OM642 oil-cooler seals harden and leak (under intake) — labour-heavy.
Fix / Workaround: Replace oil-cooler seals (intake off).
Repair cost: €400–€1100
Typically appears after: 130,000 km
Swirl-flap actuator, EGR and DPF items with age/short trips.
Fix / Workaround: Repair intake; service EGR; motorway regens.
Repair cost: €300–€1200
Mileage Thresholds
After 200,000 km: Oil-cooler + swirl-flap territory.
Pre-Purchase Checklist
- ☐Oil-cooler seal history
- ☐Swirl-flap/EGR history
- ☐The pick of the range — shared robust V6
Frequently asked questions
Is the Mercedes Benz GLK 320/350 CDI 3.0 V6 (OM642) reliable?
Maint. Sensitive — The 3.0 V6 CDI (OM642) is the smooth, effortless GLK diesel — the same robust six used across C/E-Class, ML and the Jeep Grand Cherokee, well-matched to the SUV. Budget for the OM642's signature niggles: the oil-cooler seals (in the V, under the intake) harden and leak, and the intake swirl-flap actuator fails. Plus EGR/DPF and high-mileage injection. With those addressed and good history it's a dependable, long-legged engine — the pick of the GLK range.
What are the common problems and reviews for the Mercedes Benz GLK 320/350 CDI 3.0 V6 (OM642)?
The most commonly reported problems: Oil-cooler seal leak, Intake swirl-flap / EGR / DPF.
Is a used Mercedes Benz GLK 320/350 CDI 3.0 V6 (OM642) worth buying?
Fine if serviced correctly — but it punishes neglect hard. History and the right consumables matter.