2023 Mercedes-Benz GLB-Class Complaint Log

On December 19, 2025, the vehicle showed lights that a sparkplug had misfired. The dealer notified me that in less than two full years of having the 2023 vehicle, it required a complete engine rebuild. This is the third major engine problem I have had with the vehicle with more than $20K in fees. The services performed in December 2025 repairs included Cylinder Head Assembly to Replace Engine Cylinder Head Assemble due to multiple cylinder head fault codes, including misfire, injector injection, and mixture formation code. Cylinder 2 is leaking out of the exhaust valve. Camshaft replacement and rollers due to deep scoring on both intake and exhaust cams, not by cylinder two. Exhaust valve leaking from the head while the camshafts are scoring, leading to misfiring as well.

Cylinder repair dealership said it's a known issue but Mercedes Benz said they will not cover the repair.

The windshield washer stopped working It doesn’t clean because no water comes out to do the job

I was driving on Highway on May 19th and the Panoramic Sunroof suddenly shattered

Graco Turn2Me car seat is loosening over time when installed with the vehicle seatbelt and the SnugLock Lock-Off. The vehicle seat belt was also switched to a locked mode after proper installation and did not make a difference over time. The car seat continues to loosen over time to the point where it is moving more than an inch side to side at the belt path. This can cause injury to a child during a crash. Car seat has been installed with the assistance of certified Child Passenger Safety Technicians and Instructors on multiple occasions.

The contact owns a 2023 Mercedes-Benz GLB250. The contact stated that while driving at an undisclosed speed, the vehicle lost motive power with the transmission warning light illuminated. The vehicle was towed to the dealer but was not diagnosed or repaired. Additionally, the contact stated that while driving at an undisclosed speed, the vehicle shuddered abnormally. There was no warning light illuminated. The manufacturer was made aware of the failure. The approximate failure mileage was 18,000.

Transmission switching to neutral by itself while driving on the highway. This issue has occurred twice in December 2024.

The front brakes making noise when slow stop , Merced dealer service repair 3 time and replace rotor and brakes, but the problem still making noise. they said nothing he can do. want me to report NHTSA. thanks

The contact owned a 2023 Mercedes-Benz GLB35 AMG. The contact stated that while driving at an undisclosed speed, the brakes were inoperable. The contact stated that while depressing the brake pedal, the vehicle was not braking smoothly. Additionally, the vehicle failed to accelerate as intended. The contact stated that the transmission malfunction warning light was illuminated. The contact stated that the vehicle had been taken to the dealer four times. The contact stated that the first visit with the dealer regarding the brakes, the dealer applied lubricant to the brake pedal. The contact stated that the failure was persistent. The vehicle was taken to the dealer for the second and third time, however the failure could not be duplicated. The contact stated that the failure was persistent. The vehicle was taken back to the dealer for the fourth time, and the vehicle was sold back to the dealer. The vehicle was not diagnosed or repaired by an independent mechanic or dealer. The manufacturer was made aware of the failure and a case was filed. The failure mileage was approximately 3,200.