MERCEDES-BENZ GLB 250 · model year

2021 MERCEDES-BENZ GLB 250

38 NHTSA complaints, and 4 active recalls for this specific cohort.

NHTSA overall rating

Not crash-tested

New Car Assessment Program

The 2021MERCEDES-BENZGLB 250 carries 38 consumer safety complaints in NHTSA's Office of Defects Investigation database for this specific model-year cohort. Within that volume, owners reported 0 crashes, 0 fires, 0 injuries, and 0 fatalities. No NCAP 5-star crash-test rating is available for this model year in the federal database.

Component-level analysis is where model-year complaints become actionable: the top complaint category for the 2021 GLB 250 is unknown or other with 7 filings, followed by engine (6) and electrical system (4). Concentration in one or two component groups is the classic signature of a systemic defect; a flat distribution usually reflects normal aging, warranty complaints, or isolated build-plant variability. This model year has 4 active recall campaigns, which means the manufacturer is obligated to remedy the covered defect at no charge for the life of the vehicle — the full NHTSA campaign numbers are listed below.

NHTSA currently has 15 investigation files overlapping the 2021 GLB 250. Owners comparing this cohort against neighboring years should pair the counters above with the complaint-by-year trend on the parent model page — a spike in a single year often tracks to a platform refresh, a new transmission supplier, or an updated ECU calibration. Use the related-complaint feed below to read raw owner narratives before deciding whether any pattern here affects your specific use case.

38
Complaints
0
Crashes
0
Fires
0
Injuries
0
Deaths

Total Complaints

38 filings

Crashes Reported

0 reports

Source

NHTSA ODI

Federal complaints database

Complaints vs. fleet median (215)

At or below the fleet median complaint volume.

Complaints by Component

ComponentCount
UNKNOWN OR OTHER7
ENGINE6
ELECTRICAL SYSTEM4
SUSPENSION3
POWER TRAIN3
WHEELS2
BACK OVER PREVENTION2
STRUCTURE:BODY2
FUEL/PROPULSION SYSTEM2
VISIBILITY1
AIR BAGS1
TIRES:TREAD/BELT1
SEAT BELTS1
STEERING1
VISIBILITY/WIPER1

Recalls (4)

22V36500020/05/2022

ELECTRICAL SYSTEM:SOFTWARE

Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2017-2022 CLA-Class, GLA-Class, GLE-Class, GLS-Class, SLC-Class, A-Class, AMG GT-Class, C-Class, E-Class, S-Class, SL-Class, GLC-Class, CLS-Class, GLB-Class, and G-Class vehicles. Please refer to MBUSA's recall report for specific vehicle model de

21V35400014/05/2021

BACK OVER PREVENTION: SENSING SYSTEM: CAMERA

Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2019-2021 CLA-Class, GLE/GLS-Class, A-Class, E-Class, E-Class Coupe and Convertible, GLA/GLB-Class, GLC-Class, CLS-Class, and AMG GT-Class 4-door Coupe vehicles. Please refer to MBUSA's recall report for specific vehicle model details. The MBUX m

22V23200008/04/2022

BACK OVER PREVENTION:DISPLAY FUNCTION

Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2018-2021 CLA-Class, GLE/GLS-Class, A-Class, C-Class, E-Class, E-Class Coupe/Convertible, GLA/GLB-Class, GLC-Class, and CLS-Class vehicles. Please refer to MBUSA's recall report for specific vehicle model details. The rearview camera may not disp

21V05800005/02/2021

ELECTRICAL SYSTEM:SOFTWARE

Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2016 - 2021 CLA-Class, GLA-Class, GLE-Class, GLS-Class, SLC-Class, A-Class, GT-Class, C-Class, E-Class, S-Class, CLS-Class, SL-Class, B-Class, GLB-Class, GLC-Class, and G-Class vehicles. Please refer to the Part 573 report for specific vehicle mod

Recent Complaints

20260103SERVICE BRAKES

I purchased this vehicle in May 28 2025. I certified car. I took in for oil change Nov 17-2025. Found out they had lot of issues., left front bushing arm leaking. Rt engine mount leaking. Bad brakes battery low. Bad tire rt back passage side.front wheel axle and rear wheel axle is bad and screw on the engine mount is missing. Screw and leaking..?and the vehicle needed a alignment.

20260103POWER TRAIN

I purchased this vehicle in May 28 2025. I certified car. I took in for oil change Nov 17-2025. Found out they had lot of issues., left front bushing arm leaking. Rt engine mount leaking. Bad brakes battery low. Bad tire rt back passage side.front wheel axle and rear wheel axle is bad and screw on the engine mount is missing. Screw and leaking..?and the vehicle needed a alignment.

20260103WHEELS

I purchased this vehicle in May 28 2025. I certified car. I took in for oil change Nov 17-2025. Found out they had lot of issues., left front bushing arm leaking. Rt engine mount leaking. Bad brakes battery low. Bad tire rt back passage side.front wheel axle and rear wheel axle is bad and screw on the engine mount is missing. Screw and leaking..?and the vehicle needed a alignment.

20251212POWER TRAIN

IT APPEARS AS IF THERE IS AN ISSUE WITH THE TRANSMISSION. IN THIS VEHICLE. WHEN YOU COME TO A STOP THE TRANSMISSION HAS A LOUD CLUNKING NOISE COMING FROM LEFT SIDE OF VEHICLE. THE CLUNKING OCCURS WHEN THE VEHICLE DOWNSHIFTS. IT CLUNKS FROM D4 TO D3, THEN D3 TO D2 , AND AGAIN AT D2 TO D1. I HAVE TAKEN IT TO THE DEALER NUMEROUS TIMES TO HAVE IT CHECKED. THE SERVICE MGR WENY FOR S TEST DRIVE WITH ME AND HEARD IT. I WAS THEN TOLD THE CLUNKING WAS " NORMAL" . I PURCHASED THE VEHICLE AS A CERTIFIED USED VEHICLE FROM THE SAME DEALER . THIS HAS BEEN OCCURING SINCE PURCHASE IN MAY 2024

20251212ENGINE

Engine locked up while driving out of state on the interstate. Vehicle lost all power and engine stopped functioning. Managed to pull over and stop the vehicle on the side of the interstate. Had truck towed to repair shop where they diagnosed connecting rod/crankshaft bearing failure, as well as lifter and cylinder misfire/failure on cylinder 7. Metal shavings were discovered in the oil, and engine locked up and cannot be repaired. I am currently in the process of having the engine replaced, but yes currently an inspection can still be performed, and I can provide statements and diagnostics from the mechanic. This failure put myself and my family in a scary situation. The engine was shaking violently before it stopped functioning and this made the truck very difficult to steer, not to mention this was during rush hour and we were in heavy traffic moving at speeds of 70mph+. Luckily we managed to get off the road, and to a safer location, but this left us stranded on the side of the r

20251212FUEL/PROPULSION SYSTEM

Engine locked up while driving out of state on the interstate. Vehicle lost all power and engine stopped functioning. Managed to pull over and stop the vehicle on the side of the interstate. Had truck towed to repair shop where they diagnosed connecting rod/crankshaft bearing failure, as well as lifter and cylinder misfire/failure on cylinder 7. Metal shavings were discovered in the oil, and engine locked up and cannot be repaired. I am currently in the process of having the engine replaced, but yes currently an inspection can still be performed, and I can provide statements and diagnostics from the mechanic. This failure put myself and my family in a scary situation. The engine was shaking violently before it stopped functioning and this made the truck very difficult to steer, not to mention this was during rush hour and we were in heavy traffic moving at speeds of 70mph+. Luckily we managed to get off the road, and to a safer location, but this left us stranded on the side of the r

20251210VISIBILITY/WIPER

Driving on north bound of Merritt Parkway between exit 17 and 18. Today 12/10/25 9:28 AM My panoramic sunroof exploded ! all catch on video, driver on the vehicle behind me , came to check on me; and told me the glass went over four feet up in the air and then hit his vehicle windshield, I call Mercedes Benz customer service support to report the incident and open a case, they told me to drive to the closest dealer from the incident (Mercedes Benz of Fairfield) when I arrived and show the vehicle to the technician, he was trying to tell me that was my fault and he never heard such a thing of a sunroof explosion… and was looking for a reason to blame me, I told him I got all on video due to I have a dash camera that records the our side and the inside of the vehicle.. the outside temperature was 30 degrees Fahrenheit, and the inside temperature in the vehicle was set to 69 degrees… My speed was 55 to 56 miles per hour. Light to moderate traffic, the explosion sound like a gunsho

20251130ENGINE

Engine showed signs of loss of power and excess noise. It was taken to dealership via MB roadside assistance. At the dealership, they diagnosed it with engine catastrophic failure due to metal parts found in the oil filter. At no time was the engine disassembled to ensure known defects and still under warranty parts were not the cause. Dealer estimated the repair to cost in excess of $22K. MBUSA was contacted and they made no efforts to make the situation whole. The cost estimated was for the complete engine replacement. An engine that only has 53k miles. Although all routine maintenance have been conducted, engine failure was certainly pre-mature. Issues exhibited were excessive engine vibration, loss of power and excess noise.

20251123STEERING

Escalating Safety Concern – Loud Clunking, Thumping, and Cracking from Front Axle at Low Speeds We are long-time loyal customers and currently own four identical Mercedes-Benz models. Unfortunately, one of our vehicles, a 2021 mb glb250 has recently developed severe clunking, thumping, and loud cracking noises originating from the front axle area, noticeable especially at low speeds. The problem appeared suddenly and is rapidly worsening. After researching the issue, we’ve discovered that many owners of the exact same model and model year report identical symptoms. This appears to be a widespread and recurring problem that raises serious safety concerns, particularly as it affects the front axle and is uncommon in other modern vehicles of this class and young age. Given the potential safety implications and the growing number of affected owners, we respectfully request that Mercedes-Benz investigate this issue promptly, acknowledge it as a known concern, and provide an appropria

20251123SUSPENSION

Escalating Safety Concern – Loud Clunking, Thumping, and Cracking from Front Axle at Low Speeds We are long-time loyal customers and currently own four identical Mercedes-Benz models. Unfortunately, one of our vehicles, a 2021 mb glb250 has recently developed severe clunking, thumping, and loud cracking noises originating from the front axle area, noticeable especially at low speeds. The problem appeared suddenly and is rapidly worsening. After researching the issue, we’ve discovered that many owners of the exact same model and model year report identical symptoms. This appears to be a widespread and recurring problem that raises serious safety concerns, particularly as it affects the front axle and is uncommon in other modern vehicles of this class and young age. Given the potential safety implications and the growing number of affected owners, we respectfully request that Mercedes-Benz investigate this issue promptly, acknowledge it as a known concern, and provide an appropria

20251123UNKNOWN OR OTHER

Escalating Safety Concern – Loud Clunking, Thumping, and Cracking from Front Axle at Low Speeds We are long-time loyal customers and currently own four identical Mercedes-Benz models. Unfortunately, one of our vehicles, a 2021 mb glb250 has recently developed severe clunking, thumping, and loud cracking noises originating from the front axle area, noticeable especially at low speeds. The problem appeared suddenly and is rapidly worsening. After researching the issue, we’ve discovered that many owners of the exact same model and model year report identical symptoms. This appears to be a widespread and recurring problem that raises serious safety concerns, particularly as it affects the front axle and is uncommon in other modern vehicles of this class and young age. Given the potential safety implications and the growing number of affected owners, we respectfully request that Mercedes-Benz investigate this issue promptly, acknowledge it as a known concern, and provide an appropria

20250902UNKNOWN OR OTHER

While driving, the panoramic moonroof on my 2021 Mercedes-Benz GLB 250 (VIN: [XXX] ) suddenly shattered without any visible impact or prior damage. It sounded like an explosion, and glass rained down into the vehicle. This could have caused serious injury to myself or my child. There was no indication that a rock or debris hit the vehicle. No vehicles were in front of me, and I have no history of impact damage. This seems to have happened spontaneously, and after researching the issue, I found it is a common problem across various Mercedes-Benz models. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

20250620ENGINE

In April 2025, my 2021 Mercedes-Benz GLB 250 (81,000 miles) suffered repeated engine issues caused by a cylinder head failure. The dealer attempted a cylinder head replacement, but during their own test drive after repairs, the engine completely seized and failed again on their property. This indicates a severe defect in the engine assembly that risks sudden power loss while driving, which could cause an accident. Prior to the failure, there were warning messages about misfires and rough idle. The problem has been confirmed by an authorized Mercedes-Benz dealer and the car has been kept at their shop since April, with no resolution. I am concerned this is a recurring safety defect affecting other GLB 250 vehicles. The vehicle is available for inspection and remains undriveable due to the failed engine. I request NHTSA to investigate for possible safety-related design or manufacturing defects that could cause sudden engine seizure and loss of power while driving.

20250620FUEL/PROPULSION SYSTEM

In April 2025, my 2021 Mercedes-Benz GLB 250 (81,000 miles) suffered repeated engine issues caused by a cylinder head failure. The dealer attempted a cylinder head replacement, but during their own test drive after repairs, the engine completely seized and failed again on their property. This indicates a severe defect in the engine assembly that risks sudden power loss while driving, which could cause an accident. Prior to the failure, there were warning messages about misfires and rough idle. The problem has been confirmed by an authorized Mercedes-Benz dealer and the car has been kept at their shop since April, with no resolution. I am concerned this is a recurring safety defect affecting other GLB 250 vehicles. The vehicle is available for inspection and remains undriveable due to the failed engine. I request NHTSA to investigate for possible safety-related design or manufacturing defects that could cause sudden engine seizure and loss of power while driving.

20250620POWER TRAIN

In April 2025, my 2021 Mercedes-Benz GLB 250 (81,000 miles) suffered repeated engine issues caused by a cylinder head failure. The dealer attempted a cylinder head replacement, but during their own test drive after repairs, the engine completely seized and failed again on their property. This indicates a severe defect in the engine assembly that risks sudden power loss while driving, which could cause an accident. Prior to the failure, there were warning messages about misfires and rough idle. The problem has been confirmed by an authorized Mercedes-Benz dealer and the car has been kept at their shop since April, with no resolution. I am concerned this is a recurring safety defect affecting other GLB 250 vehicles. The vehicle is available for inspection and remains undriveable due to the failed engine. I request NHTSA to investigate for possible safety-related design or manufacturing defects that could cause sudden engine seizure and loss of power while driving.

20250611SEAT BELTS

Seat belt failure.Driver side…mechanism… it feels unsafe…the retractor is not locking

20250606ENGINE

Jerking and loud noise from the engine after attempting to accelerate from a red light stop. Vehicle is idling very roughly and almost sounds like a diesel engine. Check engine light came on. Inspection at the dealership found multiple faults for camshaft positions deviating from the specified value. When the oil filter was removed, the shop reported finding some metal particles in the oil. The conclusion was that a mechanical fault caused a metal part in the engine to brake and clog up the engine. The car did not run smoothly after the jerking sound and could have caused an accident if the car was in active motion. The recommendation now is that the engine needs to be replaced.

20250606UNKNOWN OR OTHER

Jerking and loud noise from the engine after attempting to accelerate from a red light stop. Vehicle is idling very roughly and almost sounds like a diesel engine. Check engine light came on. Inspection at the dealership found multiple faults for camshaft positions deviating from the specified value. When the oil filter was removed, the shop reported finding some metal particles in the oil. The conclusion was that a mechanical fault caused a metal part in the engine to brake and clog up the engine. The car did not run smoothly after the jerking sound and could have caused an accident if the car was in active motion. The recommendation now is that the engine needs to be replaced.

20240906TIRES:TREAD/BELT

The contact owns a 2021 Mercedes-Benz GLB250 equipped with Continental Tires, Tire Line: ProContact GX SSR, Tire Line: 235/55/R18, DOT Number: A33LWXX41220. The contact stated while driving 70 MPH, the vehicle began to vibrate with a flapping sound coming from the vehicle. Despite the failure, the contact was able to drive the vehicle to the residence. The contact then drove the vehicle to an independent mechanic where three humps were discovered on the front driver’s side tire that had formed due to thread separation on the inside of the tire. The mechanic referred the contact to a dealer who then referred the contact to the Continental tire manufacturer. The manufacturer informed the contact that the tire should be sent to the headquarters for an inspection. The tire was replaced. The failure mileage was approximately 30,600.

Mileage: 30,600

20240227UNKNOWN OR OTHER

Glass that’s in between the windshield and sunroof

Compare 2021MERCEDES-BENZGLB 250 to Similar Vehicles

NHTSA Investigations

View all investigations

Frequently Asked Questions

How many complaints does the 2021 MERCEDES-BENZ GLB 250 have?
The 2021 MERCEDES-BENZ GLB 250 has 38 NHTSA complaints, 0 crashes, 0 fires, 0 injuries, and 0 deaths reported.
Are there any recalls for the 2021 MERCEDES-BENZ GLB 250?
Yes, the 2021 MERCEDES-BENZ GLB 250 has 4 recall(s). The most common affected component is ELECTRICAL SYSTEM:SOFTWARE. Recalls are issued by NHTSA and manufacturers must provide a free remedy.
What are the most common problems with the 2021 MERCEDES-BENZ GLB 250?
The most-complained component for the 2021 MERCEDES-BENZ GLB 250 is UNKNOWN OR OTHER with 7 complaints. Other frequently reported areas include ENGINE and ELECTRICAL SYSTEM.
Is the 2021 MERCEDES-BENZ GLB 250 safe to buy?
Review the complaint history, crash and fire reports, safety ratings, and recall status on this page to make an informed decision. No NHTSA crash test rating is available for this model year. Compare with other model years using the links above.
Where does this data come from?
All complaint, recall, and safety rating data is sourced from the National Highway Traffic Safety Administration (NHTSA). Complaints are filed by vehicle owners through NHTSA's Office of Defects Investigation.

Vehicle Safety Guides

Data as of 2025. Sources: NHTSA Office of Defects Investigation (ODI) complaints database, NHTSA recall campaign API, NHTSA NCAP crash-test ratings, and NHTSA FARS for fatality cross-reference.