2021 Mercedes-Benz GLB 250

29 complaints on file, page 1 of 2.

1. Filed Aug 12, 2026Failure Aug 7, 202663,000 milesWestborough, MARoof and pillars

   The contact owns a 2021 Mercedes-Benz GLB250. The contact stated that the front stationary roof panel detached from the vehicle and shattered. The vehicle was taken to the dealer but was not diagnosed or repaired. The contact became aware of a recall with a similar failure; however, the VIN was not included, and the model year was not included in a recall for the failure. The manufacturer was not made aware of the failure. The failure mileage was approximately 63,000.

   NHTSA complaint 11756454
2. Filed Apr 29, 2026Failure Apr 27, 2026Slidell, LAUnknown or other

   Family and I were driving on the interstate and heard a loud bang (like a shotgun) followed by immediate glass everywhere. The panoramic sunroof exploded. We had to drive 4 hours like this - lucky we didn’t jerk the wheel on the interstate with the noise. Absolutely sickening that this is so prevalent and Mercedes won’t do anything about it.

   NHTSA complaint 11734501
3. Filed Mar 3, 2026Failure Mar 26, 2024Bogart, GAEngine, Unknown or other

   When my car sits in the rain for long periods of time, while driving, it will automatically switch into neutral and give me a "transmission malfunction stop" & "service required do not shift gears visit dealer" sign on the dash. This has happened at least 7 times in 2 years since March 2024. The latest time it happened was last week. I will get into my car after a day at work, when it has been raining, drive a few miles and the car will switch into neutral and display those signs. This is incredibly dangerous for my safety as the driver, any passengers and any other cars on the road. While going 55+ miles an hour, my car, without any warning shifts into neutral. I have taken it to my local dealership for inspection every time that it happens and they have repeatedly told me they cannot find a fix for it and do not know why it is happening besides a electrical problem due to water. They advised me to file a claim with corporate Mercedes but that was denied. I have photos and documentation from the dealership of when I have brought it in for inspection and they have confirmed the issue. They will not help with a solution for this problem. They have told me to pull over, turn the car on and back off to get it to go away but it continues to do the same repeated problem.

   NHTSA complaint 11721700
4. Filed Feb 20, 2026Failure Jan 14, 2026Guaynabo, PR, PRSteering, Suspension, Unknown or other

   The component that appears to have malfunctioned is the front axle integral carrier (front subframe) and the related front suspension geometry, as the vehicle now exhibits a persistent pull to the left and degraded steering stability after the dealer replaced the front lower control arms, engine mounts, and performed alignments; this area of the vehicle is fully available for inspection upon request. My safety and the safety of others were put at risk because the vehicle requires constant steering correction to avoid drifting left, creating a danger of unintended lane departure and loss of control, which aligns with the steering‑related risks described in NHTSA Recall 21V990 / MBUSA 2022070009, where failure of the integral carrier can impair steering and increase crash risk. The problem has been reproduced by me on every drive, though the dealer stated they “did not find anything,” despite alignment printouts showing front camber imbalance and lack of caster correction. The vehicle has been inspected twice by the authorized Mercedes‑Benz dealer, but they did not inspect or address the front axle integral carrier even though the recall documentation shows that corrosion or structural issues in this part can affect steering performance and connection to other components. There were no warning lamps or dashboard alerts; the symptoms began immediately after the dealer’s suspension and mount repairs, and the steering pull and unstable handling have continued ever since.

   NHTSA complaint 11719310
5. Filed Jan 3, 2026Failure Nov 22, 2025Atlanta, GAPower train, Service brakes, Wheels

   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.

   NHTSA complaint 11708509
6. Filed Dec 12, 2025Failure Sep 10, 2025Madison, ALEngine, Fuel/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 road for 2 hours waiting on a tow. The vehicle was inspected by a GMC dealership initially where they only diagnosed lifter and cylinder misfire/failure. Due to the price of their quote to repair that issue, I took the vehicle to a certified mechanic, and thats when we found there was also connecting rod/crankshaft bearing failure prior to repairing the lifter/cylinder misfire. There were no prior warnings to this happening. No check engine lights, no noises, and no noticeable changes in the vehicle. Everything seemed to be operating normally.

   NHTSA complaint 11704669
7. Filed Dec 12, 2025Failure May 27, 2024Little Silver, NJPower 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

   NHTSA complaint 11704654
8. Filed Dec 10, 2025Failure Dec 10, 2025Hartford, CTVisibility/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 gunshot, that was my first impression, some one shoot at me… The dealer, told me that I should call my insurance or Mercedes Benz and the only think they can do, is to tell me how much will cost to repair the damage.. and that they will park my car on a different building so don’t get rain on it, until I decided what I want to do.

   NHTSA complaint 11704359
9. Filed Nov 30, 2025Failure Oct 13, 2025Bayamon, PREngine

   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.

   NHTSA complaint 11702151
10. Filed Nov 23, 2025Failure May 1, 2025Gilbert, AZSteering, Suspension, Unknown 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 appropriate inspection and repair at no cost to us. We love the brand and have always trusted its engineering and safety standards, which makes this experience especially distressing. We would greatly appreciate your immediate attention and a clear response on next steps.

    NHTSA complaint 11701110
11. Filed Sep 2, 2025Failure May 12, 2025San Tan Valley, AZUnknown 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)

    NHTSA complaint 11684397
12. Filed Jun 20, 2025Failure Mar 3, 2025Bushnell, FLEngine, Fuel/propulsion system, Power 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.

    NHTSA complaint 11668223
13. Filed Jun 11, 2025Failure May 29, 2025Land o Lakes, FLSeat belts

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

    NHTSA complaint 11666248
14. Filed Jun 6, 2025Failure May 28, 2025Murfreesboro, TNEngine, Unknown 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.

    NHTSA complaint 11665355
15. Filed Sep 6, 2024Failure Aug 16, 202430,600 milesWest Columbia, SCTread/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.

    NHTSA complaint 11613119
16. Filed Feb 27, 2024Failure Feb 24, 2024Spring, TXUnknown or other

    Glass that’s in between the windshield and sunroof

    NHTSA complaint 11574232
17. Filed Jan 31, 2024Failure Jan 31, 2024Massillon, OHEngine

    Cylinder Head gone bad at 35,000 miles

    NHTSA complaint 11569034
18. Filed Oct 30, 2023Failure May 20, 2023Alameda, CAUnknown or other

    My fuel tank cover would not open. Car was under warranty so MB was able to replace the motor of the fuel cap release. Problem, there is no manual release for the fuel cap so if you are low on fuel and need to fill up, you would be stranded. They need a manual release for the fuel cap for safety.

    NHTSA complaint 11552670
19. Filed Oct 24, 2023Failure Oct 6, 2023livingston, NJAir bags, Electrical system, Body

    Entire electrical system went out while driving causing check engine light to come on after the failure of system; there was no dashboard working at all when the system went out; without the dashboard out it was not certain if the vehicle was safe to drive anymore; the dealer has not been able to reproduce the problem; the vehicle has been with the dealer repair system for several weeks and have not been able to determine what happened; they have indicated that the vehicle had some type of water intrusion which short circuited the electrical system; the believes that the water entered into from the windshield area with a possible clogged water drain; there was no prior warning

    NHTSA complaint 11551607
20. Filed Aug 22, 2023Failure Aug 21, 202313,716 milesEncino, CAVisibility

    The contact owns a 2021 Mercedes-Benz GLB250. The contact stated that the vehicle was parked in the garage; however, after driving out of the garage, the contact became aware of a crack on the windshield from the rear-view mirror ten inches downward. The contact stated that the crack seemed to be on the inside over the sensors. The vehicle had not yet been diagnosed or repaired. The dealer nor manufacturer was notified of the failure. The failure mileage was 13,716.

    NHTSA complaint 11540001