2021 Mercedes-Benz GLB 250 problems and owner complaints
Explore the records behind recurring owner reports.
Key facts
29 owner complaints analyzed
11 distinct recall campaigns
30,600 mi median reported failure mileage
Scope: 2021 model year. Data snapshot: . 3 complaints include usable failure mileage.
Most common problems
Unknown Or Other is the most frequently named component, appearing in 10 of 29 complaints (34.5%). A complaint can name multiple components.
| Topic | Matching reports | Share of complaints |
|---|---|---|
| Electrical and battery issues | 5 | 17.2% |
| Transmission and shifting | 3 | 10.3% |
| Engine operation | 2 | 6.9% |
| Braking behavior | 2 | 6.9% |
| Steering behavior | 1 | 3.4% |
| Fuel system concerns | 1 | 3.4% |
Topic matches use published keyword rules. They describe mentions, including negations or comparisons, and do not confirm a diagnosis. Read the matching rules.
Component breakdown
Number of unique complaints naming each component. Top eight shown.
| Category | Count |
|---|---|
| Unknown Or Other | 10 |
| Engine | 7 |
| Electrical System | 4 |
| Suspension | 4 |
| Power Train | 3 |
| Back Over Prevention | 2 |
| Fuel/Propulsion System | 2 |
| Steering | 2 |
Unknown Or Other: 10; Engine: 7; Electrical System: 4; Suspension: 4; Power Train: 3; Back Over Prevention: 2; Fuel/Propulsion System: 2; Steering: 2
Reported problems by failure mileage
Complaint counts in mileage bands. These are not failure rates per vehicle or mile.
| Category | Count |
|---|---|
| Under 25,000 | 1 |
| 25,000 to 49,999 | 1 |
| 50,000 to 74,999 | 1 |
| 75,000 to 99,999 | 0 |
| 100,000 to 149,999 | 0 |
| 150,000 and above | 0 |
Under 25,000: 1; 25,000 to 49,999: 1; 50,000 to 74,999: 1; 75,000 to 99,999: 0; 100,000 to 149,999: 0; 150,000 and above: 0
Under 25,000 miles has the most reports with usable mileage (1). 26 complaints have missing, zero or invalid mileage.
Complaints over time
Year the complaint was filed, not the vehicle model year or incident year. The snapshot year is partial.
| Category | Count |
|---|---|
| 2021 | 1 |
| 2022 | 5 |
| 2023 | 6 |
| 2024 | 3 |
| 2025 | 9 |
| 2026 | 5 |
2021: 1; 2022: 5; 2023: 6; 2024: 3; 2025: 9; 2026: 5
Pattern summary
Unknown Or Other leads the component reports. Electrical and battery issues appears in 5 complaint narratives. Transmission and shifting appears in 3 complaint narratives. Engine operation appears in 2 complaint narratives. Use these patterns to inspect individual reports and prepare questions for a mechanic.
Calculated from recorded counts. An AI narrative has not been published for this selection.
Complaint evidence
Examples provide context, not a representative sample or a verified diagnosis.
Owner report 11455730 · 2022-03-08 (March 8, 2022)
The contact owns a 2021 Mercedes-Benz GLB250. The contact received notification of NHTSA Campaign Number: 21V354000 (Back Over Prevention, Electrical System) however, the part to do the recall repair was not yet available. The local dealer was contacted. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the issue and informed the contact that the part was not yet available. The contact had not experienced a failure. Parts distribution disconnect.
Owner-reported narrative. Look up ODI 11455730 at NHTSA ↗
Owner report 11503216 · 2023-01-23 (January 23, 2023)
The contact owns a 2021 Mercedes-Benz GLB250. The contact received notification of NHTSA Campaign Number: 21V354000 (Back Over Prevention, Electrical System) however, the part to do the recall repair was unavailable. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The contact stated that several unknown local dealers were contacted, and the contact was referred to the manufacturer for further assistance. The manufacturer was contacted, and a case was opened. The contact had not experience…
Owner-reported narrative. Look up ODI 11503216 at NHTSA ↗
Owner report 11496487 · 2022-12-07 (December 7, 2022)
Front right ball joint separated from lower control arm with no advance warning and the drive shaft was disconnected from the vehicle body. I was travelling at about 15 mph in a straight line through an intersection on a flat surface with no potholes. Then I saw a warning of a transmission fault in my instrument cluster, followed by a loud grinding sound. My car then came to a stop and I was unable to move the vehicle in Forward or Reverse gear. I ignition cycled the vehicle and tried forward/reverse, then someone told me that my front right …
Owner-reported narrative. Look up ODI 11496487 at NHTSA ↗
Owner report 11704654 · 2025-12-12 (December 12, 2025)
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 O…
Owner-reported narrative. Look up ODI 11704654 at NHTSA ↗
Owner report 11668223 · 2025-06-20 (June 20, 2025)
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 Me…
Owner-reported narrative. Look up ODI 11668223 at NHTSA ↗
Owner report 11702151 · 2025-11-30 (November 30, 2025)
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 …
Owner-reported narrative. Look up ODI 11702151 at NHTSA ↗
Owner report 11665355 · 2025-06-06 (June 6, 2025)
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…
Owner-reported narrative. Look up ODI 11665355 at NHTSA ↗
Owner report 11708509 · 2026-01-03 (January 3, 2026)
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.
Owner-reported narrative. Look up ODI 11708509 at NHTSA ↗
Owner report 11719310 · 2026-02-20 (February 20, 2026)
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 d…
Owner-reported narrative. Look up ODI 11719310 at NHTSA ↗
Owner report 11552670 · 2023-10-30 (October 30, 2023)
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.
Owner-reported narrative. Look up ODI 11552670 at NHTSA ↗