2022 Mercedes-Benz GLC: What to check before buying

Hard shaking comes through the wheel for several seconds after the front tires hit potholes, cross joints, dips or patched pavement. It shows up mostly at highway speeds, often between 45 and 65 mph, and some owners say the whole body vibrates and steering feels less effective. Reports start as early as 3,100 miles. Dealers have tried software updates, a steering wheel bracket replacement, new tires and alignment, yet many owners say the shake continues. One complaint is crash-related, and another describes a complete loss of steering on a wet expressway.

Most reports concern recall campaign 23V445000 for the gasoline fuel system. Owners received the notice, but the repair part was not available, and dealers and the manufacturer confirmed the shortage. None of these owners report an actual failure. They complain that the wait for the fix has gone on too long. One separate report is crash-related with an injury: the steering pulled to the right at about 30 mph with no warning light, the SUV hit a parked car, and the engine stalled.

The car loses power on the road, bucks and vibrates, lights up the dash, and has to be pulled over. Several reports center on fuel pump recall 23V445: dealers could not complete the repair, didn't respond, or kept the car for days. In one case the engine still stopped on the highway with a low fuel pressure message after the recall pump replacement. Owners point to the crash and injury risk the recall itself describes.

The fuel gauge drops to empty with fuel still in the tank, and in one case the engine then shut off on an expressway. A replaced fuel tank sensor did not fix it. Other reports describe sudden shifts to neutral, ticking and power loss after the fuel pump recall work, and windows, moonroof and radio operating on their own even after a software update. One complaint involves smoke from under the hood followed by a fire at low speed. Another is a crash with injury, where wipers and camera activated by themselves and the car accelerated unexpectedly.

The engine stops responding to the accelerator, sometimes at highway speeds of 60 to 76 mph, and the car slows down on its own. Warning lights often come on first. In one case a "do not shift" warning appeared, the shifter seized, the wheels locked, and the car was towed. Another case happened at about 51,519 miles. Owners also describe a diesel-like clatter at idle and while driving, sometimes with a coolant warning, and say dealers found no fault because no codes were stored.

Misfires and sudden power loss force drivers to pull over, shut down and restart to recover, while the check engine light flashes. These episodes happen both on surface streets and on highways. Replacing spark plugs and coils and flushing the transmission did not stop one recurrence. In another case the misfires were traced to a valve seat failure needing a full cylinder head replacement at around 60,000 miles, just outside the warranty.