Mercedes-Benz GLK 350
Four-valve V6 with variable valve timing. Smooth and powerful. Known for balance shaft wear (revision sprocket) on early build years. Balance shaft gear problem addressed by Mercedes with a recall.
Adequately Powered
200 kW in an SUV is adequate. Not exciting, but not underpowered either.
Engine Weaknesses 6
The plastic balance shaft sprocket on the M272 wears prematurely from the timing chain. The right cylinder bank goes out of timing. Affected up to end of October 2006.
Symptoms: Fault codes P0016/P0017 (camshaft right bank), chain rattling, rough running at idle, in extreme cases engine damage
Alongside the balance shaft issue the M272 shows premature timing chain stretch. Chain wear on softer sprockets leads to timing deviations.
Symptoms: Chain noise especially on cold start, camshaft fault codes, rough running, engine irregularities
Four camshaft adjuster solenoids (two per cylinder bank) develop leaks; oil creeps into the wiring harness as far as the ECU. Repair costs up to €1,700 documented.
Symptoms: CEL, oil traces at camshaft connectors, lambda sensor failure due to oil contamination, non-specific faults that recur
Plastic components of the M272 variable intake system become brittle and break. The intake flap linkage snaps and sets fault code P2006.
Symptoms: Fault codes P2004/P2005/P2006 (intake flap), slight power loss, check engine light
The thermostat on the M272 preferentially fails in the open position. Operating temperature is not reached; especially on motorway runs temperature drops to 75–80°C.
Symptoms: Engine doesn't reach 90°C after 10–20 km, coolant temperature fluctuates heavily, reduced heater output, fault code P0128
The hydraulic engine mounts on the M272 lose their damping effect with age. Jerky movements are especially apparent when lifting off the throttle and during gear changes.
Symptoms: Vibrations in steering wheel and gear lever during load changes, judder on gear changes, droning at low revs
Vehicle Weaknesses 7
OM642 diesel oil cooler tends to develop leaks at high mileage. Oil traces under the gearbox are a warning sign. Repair requires 7 hours of labour through complete disassembly.
Internal corrosion forms inside the hollow profile of the rear axle carrier behind the rubber mount. Structural integrity at risk with advanced infestation. Mercedes frequently covers repair under goodwill.
Brake lines corrode at line brackets where dirt and salt accumulate. Replacement requires lowering the rear axle, possibly also the fuel tank. Workshop costs 220–2,000 EUR.
Handbrake seizes when not used regularly. Brake lines corrode with age. Brake problems increase with vehicle age. Brake pads wear quickly on petrol models.
GLK is heavier than the related W204, resulting in higher wear on suspension bushings. Front control arm and anti-roll bar mounts particularly affected. Xenon headlight brackets vibrate.
Electric tailgate no longer opens fully or at all, control unit must be replaced. COMAND infotainment system freezes. Rear window wiper jams. Reversing camera fails sporadically.
Dirt accumulates under plastic covers and around retrofitted tow bars, leading to rust formation. Underbody in areas without regular inspection is susceptible.
Reports & Tests
944 owner complaints filed with NHTSA (2008–2015). Most reported: Airbags (648), Fuel System (75), Other (40).