2023 Mercedes-Benz GLB-Class owner complaints

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

Safety Risk - Twice I was almost hit because my car didn't take off. O'REILLY Veri Scan Results - Free Emissions Status: Red Primary DTC: Mixture Formation (Cylinder 4) is irregular P219F: Fuel injectors measure and atomize fuel mixed with incoming air and sent to combustion chambers. Cylinder 4 PSI at 40 Mercedes Benz of San Juan $300 diagnostic Cylinder head needs to be replaced. Safety Risk - Twice I was almost hit because my car didn't take off. Problem has been confirmed by dealer. Not inspected by manufacturer, etc. Prior to failure there were no signs. Check Engine light came on and that is when it got checked at 55, 715 miles, soon after warranty ended.

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.

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.

Reporting because I see reports on other searches of this happening on other Mercedes Benz various years and models, the front stationary roof panel has shattered, cracked. I was lucky, my vehicle is only cracked (leaving my windshield components open to the weather , ie rain in Washington). Others report shattering while driving and having injuries from blowing glass. This appears to be an ongoing problem with Mercedes, they want over $2000 to fix a common problem with their vehicles.

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

My 2023 Mercedes-Benz GLB 250 is experiencing engine misfires and fault codes consistent with a known cylinder head defect that is the subject of a recall affecting 2022 and earlier models. A certified mechanic has confirmed the issue aligns with the recall defect. Despite identical symptoms and engine configuration, my VIN is excluded. The condition results in loss of power and creates a potential safety hazard while driving. The following codes are referenced in the Mercedes recall and by recorded by the auto repair shop that provided an estimate for the repair: P1CEF85 - Injector injection quantity adjustment for cylinder balancing has almost reached the upper limit value at atleast one cylinder. P1CE577 - Injector injection quantity adjustment for uniform mixture formation has detec

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.

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.

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

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

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