Mercedes-Benz GLK X204 — Reliability

X204 2010–2015 2 engines

Reliability Summary

Best engine OM651 (late) — 72/100 ACCEPTABLE
Worst engine OM651 (early) — 66/100 CAUTION
Average reliability 69/100

Engine Comparison

Engine Reliability Score Verdict Known Issues
OM651 (late)
2.1L Diesel I4 		72/100 ACCEPTABLE Piezo injector failure — 204 PS (250 CDI / 250 d) variant +6
OM651 (early)
2.1L Diesel I4 		66/100 CAUTION Timing chain stretch and tensioner wear (rear-mounted chain) +3

Engines in this model

ACCEPTABLE 72

OM651 (late)

2.1L Diesel I4

The W205/W176-era OM651. Solenoid injectors on the 136 and 170 PS versions (the 204 PS 250 d kept pi...

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CAUTION 66

OM651 (early)

2.1L Diesel I4

The 2008-2014 OM651. The 220 CDI (to 2010/11) and 250 CDI had failure-prone piezo injectors, the 200...

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Known Issues Across All Engines

Issue Engine Severity Onset
Piezo injector failure — 204 PS (250 CDI / 250 d) variant OM651 (late) high 50,000 km
Timing chain and tensioner wear (rear-mounted simplex chain) OM651 (late) high 150,000 km
Chain tensioner seal ring leaks oil — recall for Feb-Nov 2014 build OM651 (late) high —
DPF blockage — city driving concern OM651 (late) high 60,000 km – 120,000 km
Coolant loss — cylinder-head coolant connector and water pump OM651 (late) moderate —
AdBlue / SCR faults: NOx sensors, crystallised dosing nozzle OM651 (late) moderate —
EGR valve fouling OM651 (late) moderate 80,000 km – 150,000 km
Timing chain stretch and tensioner wear (rear-mounted chain) OM651 (early) critical 150,000 km
DPF + EGR fouling (city use) OM651 (early) high 60,000 km – 120,000 km
Piezo injector failure — 220 CDI (to 2010/11) and 250 CDI OM651 (early) high 50,000 km
Water pump leak (March-July 2009 build) and cylinder-head coolant stub OM651 (early) moderate —

FAQ

Is the Mercedes-Benz GLK reliable?

The Mercedes-Benz GLK has 2 engine options with reliability scores ranging from 66/100 (CAUTION) to 72/100 (ACCEPTABLE). Average reliability: 69/100.

Which Mercedes-Benz GLK engine is most reliable?

The OM651 (late) is the most reliable engine in the Mercedes-Benz GLK, scoring 72/100 (ACCEPTABLE).

What problems does the Mercedes-Benz GLK have?

Across all engine variants, the Mercedes-Benz GLK has 11 known issues. The most common are related to Piezo injector failure — 204 PS (250 CDI / 250 d) variant, Timing chain and tensioner wear (rear-mounted simplex chain), Chain tensioner seal ring leaks oil — recall for Feb-Nov 2014 build.