2022 Mercedes-Benz CLA Reliability Report

The main complaints are stalling and limp mode. The engine loses power on highways and surface streets, sometimes with no warning and sometimes after a yellow temperature gauge or check engine light. Early cases appear between about 1,000 and 10,000 miles. A separate pattern involves misfires from valve seat wear that require a full cylinder head replacement, showing up at high mileage just past warranty. Owners report bills from $7,200 to over $10,000. Many excerpts describe GLC and GLE models.

The common failure is power loss at speed. The car won't accelerate, slips into neutral or stalls, sometimes with a transmission or 48-volt warning, and one freeway stall ended in a rear-end crash. Other reports describe misfires and rough idle blamed on cylinder head valve seat wear in 2.0-liter turbo engines, fuel injectors replaced twice, a diesel-like engine noise, and unintended acceleration while turning. Dealers often find no fault or prescribe a software update. Most excerpts name the GLC300 or GLE350.

Phantom braking is the most common complaint. The car brakes hard or stops with nothing ahead, at speeds from about 30 to 70 mph, which risks a rear-end collision. Owners also report driver aids that shut off with "sensors dirty" or "camera view restricted" messages, adaptive cruise that speeds up after misreading speed limit signs, and one crash where Active Brake Assist did not act. Dealers often find no fault or say the system works as designed. Many filings name the C300, GLC300, GLE350 or S580.

The reports fall into two groups. In one, brakes seize after rain, a car wash or several days parked. The car then needs heavy throttle to move and breaks free with a jolt or a screech, and one dealer reportedly said there is no fix. In the other, automatic braking stops the car with nothing ahead. A few owners describe a soft pedal that sinks to the floor, including one freeway crash with an injury. Another describes a clunk felt through the pedal on a nearly new car.

The most serious reports involve blowouts and sidewall bubbles on large 21-inch wheels with low-profile Pirelli tires. They often follow ordinary potholes and sometimes bend or ruin the rims. Other owners say run-flat and original tires wore out early and needed replacement between 18,000 and 26,000 miles, and that stored tires showed tread separation and dry cracking with under 4,000 miles on them. Dealers often decline to help, so owners pay for replacements themselves. Most excerpts name the S-Class and GLE.

These reports describe two opposite failures. In the first, cruise control misreads speed limits. It either brakes hard on the interstate when the displayed limit suddenly drops or tries to accelerate far above the posted limit. In the second, the car won't accelerate, stalls at highway speed, or slips into neutral with a transmission malfunction message, which one dealer traced to a needed software update. One crash with an injury involved unintended acceleration into a wall at about 5,000 miles. Several excerpts name the S-Class, GLB and GLE.

All three reports describe front air bags that did not deploy in frontal or front-corner collisions. Occupants suffered neck, shoulder and head injuries, including a concussion. Owners say no warning lights appeared before the crashes, and one mentions intermittent electrical faults beforehand. None of the filings gives a confirmed cause. The vehicles named include the GLE350 and CLS450.