2021 Mercedes-Benz GLB 250

Problems, Recalls & Reliability Report

Above Average

Quick Summary

The 2021 Mercedes-Benz GLB 250 has 44 owner complaints filed with NHTSA — that's 0.6x the segment average of 80. The most common issue is other problems (23% of all complaints), specifically: on september 3, 2022 while traveling east on al highway 110 the sunroof exploded as i was driving. notified montgomery county sheriff department but they refuse to do a report because it wasn’t an accident. the dealership said something had to hit the sunroof for it to shadder. explained to the serv.

Total Complaints

Recalls Issued

—/5

Safety Stars

0.6x

vs Segment Avg

Known Problems

OTHER

10 complaints

23%

• On September 3, 2022 while traveling east on AL highway 110 the sunroof exploded as i was driving. Notified Montgomery county sheriff Department but they refuse to do a report because it wasn’t an accident. The dealership said something had to hit the sunroof for it to Shadder. Explained to the serv
• The car has 29,000 miles and I took it on a two day trip across part of the country. It was driven hard but had a oil change before leaving. After arriving home it started to sputter and have no "energy". I had the cabin filter and engine filter changed and another oil change just in case. took
• 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.

Typical onset: 50K miles Est. repair: $500

“On September 3, 2022 while traveling east on AL highway 110 the sunroof exploded as i was driving. Notified Montgomery county sheriff Department but they refuse to do a report because it wasn’t an accident. The dealership said something had to hit the sunroof for it to Shadder. Explained to the serv”

— NHTSA complaint filing

ENGINE

7 complaints

16%

• We purchased a brand new Mercedes GLB in January 2021, I noticed the car started to shake. On our way leaving Zion National Park, the car started shaking really hard and the engine light turned on. The car wouldn't accelerate. We had to pull over on the side of the road. We barely made it to the dea
• Cylinder Head gone bad at 35,000 miles
• 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

Typical onset: 50K miles Est. repair: $500

“We purchased a brand new Mercedes GLB in January 2021, I noticed the car started to shake. On our way leaving Zion National Park, the car started shaking really hard and the engine light turned on. The car wouldn't accelerate. We had to pull over on the side of the road. We barely made it to the dea”

— NHTSA complaint filing

SUSPENSION

4 complaints

• This vehicle was purchased new, in cash, from the Mercedes-Benz dealership in Bellevue, WA. It was delivered to me, without being warned about the car being equipped with summer tires, the state of Washington has continuous rain, snow, and ice in a regular basis throughout the years, summer tires ar
• 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 i
• 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 cra

Typical onset: 50K miles Est. repair: $500

“This vehicle was purchased new, in cash, from the Mercedes-Benz dealership in Bellevue, WA. It was delivered to me, without being warned about the car being equipped with summer tires, the state of Washington has continuous rain, snow, and ice in a regular basis throughout the years, summer tires ar”

— NHTSA complaint filing

ELECTRICAL

4 complaints

• 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
• 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 f
• The horn randomly starts honking while driving posing a serious safety risk. it makes driving the vehicle seem like it is stolen.

Typical onset: 50K miles Est. repair: $500

“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 ”

— NHTSA complaint filing

TRANSMISSION

3 complaints

• 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 indica
• 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 TAKE
• 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 t

Typical onset: 50K miles Est. repair: $500

“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 indica”

— NHTSA complaint filing

Estimated Repair Costs

OTHER(~50K mi)

$500

ENGINE(~50K mi)

$500

SUSPENSION(~50K mi)

$500

ELECTRICAL(~50K mi)

$500

TRANSMISSION(~50K mi)

$500

Estimates based on average reported repair costs. Actual costs vary by location, shop, and severity.

🔍 Pre-Purchase Inspection Checklist

Based on 44 owner complaints for this specific year, here's what to check or ask about:

☐
OTHER: On September 3, 2022 while traveling east on AL highway 110 the sunroof exploded as i was driving. Notified Montgomery county sheriff Department but they refuse to do a report because it wasn’t an accident. The dealership said something had to hit the sunroof for it to Shadder. Explained to the serv
Typically appears around 50K miles. Repair cost ~$500
☐
ENGINE: We purchased a brand new Mercedes GLB in January 2021, I noticed the car started to shake. On our way leaving Zion National Park, the car started shaking really hard and the engine light turned on. The car wouldn't accelerate. We had to pull over on the side of the road. We barely made it to the dea
Typically appears around 50K miles. Repair cost ~$500
☐
SUSPENSION: This vehicle was purchased new, in cash, from the Mercedes-Benz dealership in Bellevue, WA. It was delivered to me, without being warned about the car being equipped with summer tires, the state of Washington has continuous rain, snow, and ice in a regular basis throughout the years, summer tires ar
Typically appears around 50K miles. Repair cost ~$500
☐
ELECTRICAL: 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
Typically appears around 50K miles. Repair cost ~$500
☐
General: Get a pre-purchase inspection from an independent mechanic ($100-$200)