2021 Mercedes-Benz AMG GLB35 Problems
Owner-reported complaints filed with NHTSA, grouped by component
Data refreshed
What this page shows
Everything below is an owner-reported complaint submitted to NHTSA about the 2021 Mercedes-Benz AMG GLB35, grouped by the component NHTSA recorded on the report. These are not confirmed defects, and they are not recalls. NHTSA does not verify most reports before publishing them, and a category with more reports in it is not evidence that a part is defective.
Complaints are reports submitted by owners and drivers to NHTSA. They are not verified and do not establish that a defect exists.
Reports by component
Ranked by how many owner reports name each component category
- Brakes116.7%
- Engine116.7%
- Other / unspecified116.7%
- Powertrain (other)116.7%
- Suspension116.7%
- Visibility116.7%
Percentages are of component mentions. A single complaint can name more than one component, so these do not sum to the total complaint count.
Each component in detail
What the reports in each category say, in the owners' own words
Brakes
Reports naming service brakes, the antilock braking system, brake hoses, master cylinders or the parking brake.
From owner reports, verbatim
The contact owned a 2021 Mercedes-Benz GLB35. The contact stated while driving at 35 MPH, the brake pedal was depressed; however, the vehicle failed to stop as intended. There was no warning light illuminated. The contact stated that neither the dealer nor an independent mechanic was contacted. The vehicle was not diagnosed or repaired. The contact stated that the vehicle was serviced months before the failure. The manufacturer was not made aware of the failure. The failure mileage was approximately 52,000.
Too few reports in this category for a page of its own — they appear in the full complaint list.
Engine
Reports naming the engine itself — including stalling, misfires, oil consumption, cooling and internal engine components.
From owner reports, verbatim
On 4/13/25 while driving my car on the highway, along with my 2 young children, I began to hear what initally sounded like a "flapping" noise. I rolled the windows down and after a minute or 2 the sound got lounder. There was never a warning or any type of safety icon that appeared on the control panel, nor any driving performance issue before hand. Shortly after the initial noise I could tell the car was struggling to accelerate. I wasn't near an exit during this time and began to panic in fear the car would shut down and I had no safe place to pull over on that stretch of highway. The noise turned into a banging within another min or so and I finally noticed an exit up ahead. Almost immediately as I excited the highway, the car completely shut down with me having practically no control of the steering wheel and unable to put the car into neutral. I coasted to the stop sign at the end of the exit ramp. The car would not restart after 2 attempts, I stepped out to see a massive amount of oil coming from under the car. The car recently had the 4th cylinder head replaced in Jan 2025 and was in the shop for almost 1 month. I was assured the engine was safe to drive after that repair. It has remained unserviced at the dealership since 4/13/25 and was informed it has catastrophic engine failure due to a thrown rod with Cylinder 2 being the "source of the failure." The dealership has quoted a $28k+ repair bill and Mercedes corporate has refused to replace it with a "goodwill" gesture. Only offering $1,500 toward repairs and no reimbursement for any of the 4 rental cars Ive obtained since my vehicle has been inoperable. I was not informed at the time of my purchase about any defects on the M260 engines faulty cylinder head & Mercedes extending a warrenty due to such. They are refusing to accept liability for the cacade of damage & ultimate engine failure steming from now cylinder 2. This event risked the lives of my children's and myself due to Mercedes negligence.
Too few reports in this category for a page of its own — they appear in the full complaint list.
Other / unspecified
Reports whose component NHTSA recorded as unknown, or that do not map to one of the categories above.
From owner reports, verbatim
The contact owns a 2021 Mercedes-Benz AMG GLB35. The contact stated he became aware that 3 out of 4 of the wheel-hub caps were missing. The contact called the local dealer and made them aware of the failure. The vehicle was not diagnosed or repaired. Upon investigation, the contact associated the failure with NHTSA Campaign Number: 20V800000 (Wheels) however, the VIN was not included. The manufacturer had not been informed of the failure. The failure mileage was approximately 22,000. Consumer is still waiting for trim replacement.
Too few reports in this category for a page of its own — they appear in the full complaint list.
Powertrain (other)
Powertrain reports that are not specifically the engine or transmission — driveshafts, axles, transfer cases and differentials.
From owner reports, verbatim
The contact owns a 2021 Mercedes-Benz AMG GLB35. The contact stated that while reversing down the driveway at approximately 4 MPH, the contact turned the steering wheel to the left and the vehicle started losing motive power. The contact stated that the RPMs were extremely high and the vehicle almost stalled. The contact stated no warning light was illuminated. The contact stated that the failure was intermittent and occurred at slower speeds between 3 and 6 MPH. The contact had taken the vehicle to a local dealer, where it was diagnosed and determined that the driver's side front axle had failed and needed to be replaced. The vehicle was not repaired. The contact researched online and related the failure to a manufacturer's recall for replacing the front axle integral carrier. The manufacturer was informed of the failure and advised the contact that the vehicle was not included in the manufacturer's recall selection. The manufacturer referred the contact to the NHTSA Hotline for assistance. The failure mileage was approximately 55,000.
Too few reports in this category for a page of its own — they appear in the full complaint list.
Suspension
Reports naming suspension components — springs, struts, shocks, control arms and related hardware.
From owner reports, verbatim
The contact owns a 2021 Mercedes-Benz AMG GLB35. The contact stated that while reversing down the driveway at approximately 4 MPH, the contact turned the steering wheel to the left and the vehicle started losing motive power. The contact stated that the RPMs were extremely high and the vehicle almost stalled. The contact stated no warning light was illuminated. The contact stated that the failure was intermittent and occurred at slower speeds between 3 and 6 MPH. The contact had taken the vehicle to a local dealer, where it was diagnosed and determined that the driver's side front axle had failed and needed to be replaced. The vehicle was not repaired. The contact researched online and related the failure to a manufacturer's recall for replacing the front axle integral carrier. The manufacturer was informed of the failure and advised the contact that the vehicle was not included in the manufacturer's recall selection. The manufacturer referred the contact to the NHTSA Hotline for assistance. The failure mileage was approximately 55,000.
Too few reports in this category for a page of its own — they appear in the full complaint list.
Visibility
Reports naming windshields, glass, wipers, defrosters and mirrors.
From owner reports, verbatim
I was driving home on a residential street at approximately 30 MPH. I heard a loud pop or bang sound coming from the top middle area of my windshield. I checked for any windshield damage, observed none. I thought the whole noise strange as nothing had hit my car or windshield. A couple days later I noticed that the glass panel between the windshield and sunroof, was completely shattered, with a horizontal crack running across the panel. I also noticed that the framing between the panel and windshield was not right. It sort of was "popped" outward. There was no warning regarding this failure. I had hand washed the vehicle 3 days prior and everything looked fine. I have had conversations with my local dealer regarding this issue and so far, am getting considerable push back, that this is my problem. Even though this problem seems very similar to the once experienced by the MB 2017-2020 C class, where this panel failed, and the sunroofs blew off. I am taking the car in to the dealer today for them to look at.
Too few reports in this category for a page of its own — they appear in the full complaint list.
Higher-selling and older vehicles accumulate more reports. Counts are not failure rates and are not directly comparable between vehicles that sold in very different numbers.
Elsewhere on this vehicle
Data sources
- NHTSA Office of Defects Investigation — owner-reported complaints and the components recorded on them
Data on this page last refreshed .