EngineHigh
ML250 and ML350 diesel AdBlue and NOx sensor faults
- Typically appears
- 60,000+ miles
- What to inspect
- Check for AdBlue warnings and a restart countdown
- Typical repair
- Electrical diagnosis & module repair · £120–£900
Is the 2011–2015 Mercedes-Benz M-Class reliable?
Scored from 6 documented faults · reviewed by the VehicleFaults Research Team
Quick answer
6.3/ 10
MixedOn our documented-fault scoring the Mercedes-Benz M-Class rates 6.3 out of 10 · mixed. We hold 6 known faults for it and 2 are rated high severity, so the risk is real but contained. The weak points cluster around engine, suspension and transmission. A well-serviced example with evidence for the big-ticket items is usually a safe buy; the score describes the model, not the specific car in front of you.
Verdict · Negotiate · budget for the known faults
What the score is built from
- Critical
- 0
- High
- 2
- Medium
- 2
- Low
- 2
Weak points cluster around engine, suspension, transmission, electrical.
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Build the inspection planThe faults that decide it
SuspensionHigh
Airmatic air suspension leaks on cars fitted with it
- Typically appears
- 70,000+ miles
- What to inspect
- Check the car stays level after standing
- Typical repair
- Suspension refresh (per axle) · £250–£1,100
EngineMedium
Oil leaks from the oil cooler and cam covers
- Typically appears
- 80,000+ miles
- What to inspect
- Look under the engine for fresh oil
- Typical repair
- Oil leak trace & seal / gasket · £180–£700
TransmissionMedium
7G-Tronic gearbox harsh shifts and conductor plate faults
- Typically appears
- 80,000+ miles
- What to inspect
- Feel for clunks and check for gearbox warning lights
- Typical repair
- Diagnostics & follow-on repair · £90–£700
ElectricalLow
Infotainment and keyless entry faults
- Typically appears
- Age-related
- What to inspect
- Test every screen and door handle
- Typical repair
- Infotainment repair or software fix · £120–£1,200
Costs are indicative UK independent-garage bands for budgeting and negotiation · never a quote.
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