3.0 CRD V6 (OM642, Mercedes)
2005–2010 · diesel · 2987cc · 218hp
Engine codes: OM642
Reliability, common problems and owner reviews for the Jeep Grand Cherokee 3.0 CRD V6 (OM642, Mercedes). Check this before you buy used.
The WH/WK diesel is the Mercedes OM642 V6 — fundamentally a good engine (200,000+ mile examples exist), but it has the OM642 signature jobs plus diesel-specific weak points: injectors and the high-pressure pump weaken at 150,000–200,000 km (coking/leaks → rough running, black smoke), the swirl motor/vacuum pump can chatter, and the oil cooler seals leak. Injectors must be re-coded if replaced. Strong with full history; budget for the known repairs.
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 GLK— 320/350 CDI 3.0 V6 (OM642)224hp
- Mercedes-Benz Vito / Viano— 3.0 CDI V6 (OM642)224hp
- 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
Injectors coke up and leak; HP pump weakens — rough running, black smoke, high fuel use. Injectors need ECU re-coding if replaced.
Fix / Workaround: Scan before buying; budget for injectors/HP pump; ensure re-coding.
Repair cost: €400–€1800
Typically appears after: 150,000 km
OM642 oil cooler seals (in the V) leak — labour-heavy.
Fix / Workaround: Replace oil cooler seals with updated parts.
Repair cost: €500–€1200
Typically appears after: 130,000 km
Swirl motor chatter / vacuum pump failure → poor performance.
Fix / Workaround: Replace swirl motor / vacuum pump.
Repair cost: €200–€700
Mileage Thresholds
After 150,000 km: Injector/HP-pump attention.
Pre-Purchase Checklist
- ☐Scan for injector/fuel-system codes
- ☐Inspect oil cooler leak
- ☐Cold-start: black smoke / rough running
- ☐The decent Mercedes-engined diesel with full history
Frequently asked questions
Is the Jeep Grand Cherokee 3.0 CRD V6 (OM642, Mercedes) reliable?
Maint. Sensitive — The WH/WK diesel is the Mercedes OM642 V6 — fundamentally a good engine (200,000+ mile examples exist), but it has the OM642 signature jobs plus diesel-specific weak points: injectors and the high-pressure pump weaken at 150,000–200,000 km (coking/leaks → rough running, black smoke), the swirl motor/vacuum pump can chatter, and the oil cooler seals leak. Injectors must be re-coded if replaced. Strong with full history; budget for the known repairs.
What are the common problems and reviews for the Jeep Grand Cherokee 3.0 CRD V6 (OM642, Mercedes)?
The most commonly reported problems: Injector / HP pump weakness (150–200k km), Oil cooler seal leak, Swirl motor / vacuum pump.
Is a used Jeep Grand Cherokee 3.0 CRD V6 (OM642, Mercedes) worth buying?
Fine if serviced correctly — but it punishes neglect hard. History and the right consumables matter.