Engine misfired in operation requiring an emergency stop while on a mountain road. Severe check engine light turned on (Mercedes has a two stage check engine light). Vehicle was parked for 20 minutes and battery was disconnected. This appeared to fix the issue. Vehicle was brought to dealer. Dealer stated the cylinder head for early 2021 GLA 250 engines had a casting flaw that result in hot…
2021 Mercedes-Benz GLA-Class engine problems
moderate Owners of the 2021 Mercedes-Benz GLA-Class have filed 5 NHTSA complaints about the engine at roughly $3,100 to repair (U.S. federal records, as of October 2026). Source: NHTSA Office of Defects Investigation. See engine across all vehicles →
Complaints
5
Recalls
0
Avg fix
$3,100
| Model year | engine complaints |
|---|---|
| 2017 GLA-Class | 4 |
| 2018 GLA-Class | 10 |
| 2021 GLA-Class (this page) | 5 |
What stands out
Engine accounts for 22% of all owner complaints filed against this vehicle, across 3 categories tracked.
No new NHTSA engine complaint has been filed on this vehicle in over 3 years — the issue may be aging out of the active population.
What owners are reporting 4 most recent
On 7/17/26, while driving at highway speed, the check engine light illuminated and the vehicle lost power and shut off. I safely pulled over. It would not restart; a red battery warning displayed. Towed to Mercedes-Benz of Wilkes-Barre, RO #8388432. Dealer found battery severely discharged, replaced it, then found engine would not turn by hand. Diagnosis: internal engine damage/seized;…
I purchased this car approx 3 months after real issues began. My car would have issues idling where it would sometimes turn off at stop lights and require multiple reignition attempts before proceeding. This would also happen when the auto-start feature (anti-idle/gas saving) was engaged (which is the default in the system) and this posed major safety concerns. The unstable idling of the car…
See attached document for complaint
Had engine trouble with your 2021 Mercedes-Benz GLA-Class?
File a complaint with NHTSA → It's free, official, and how every report above got here — owner filings are the federal safety record this page is built on.
Common questions
How serious is the engine problem on the 2021 Mercedes-Benz GLA-Class?
It's a documented issue but not catastrophic. 5 complaints have been filed. Repairs average $3,100 and most owners catch it before it causes a breakdown.
At what mileage does the engine typically fail?
Mileage data is limited for this issue. Owners report failures across a wide range, suggesting cause is more about driving conditions and maintenance than mileage alone.
What does it cost to fix?
Independent shops typically charge around $3,100 for engine repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to engine?
No active recalls currently cover engine issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.
Related
Complaint and recall data sourced from the National Highway Traffic Safety Administration (NHTSA)
public records database. Verify the raw federal record at
nhtsa.gov/vehicle/2021/Mercedes-Benz/GLA-Class.
Severity ratings are derived from reported crashes, fires, injuries, and fatalities. Repair cost estimates are
independent-shop national averages and may differ in your area. Some links on this page are affiliate links.