There are 3 owner-reported engine complaints for the 2017 Mercedes-Benz GLS-Classin NHTSA's database. These are unverified consumer reports and may not reflect confirmed defects.
On July 23, 2025, I drove my Mercedes-Benz GLS 450 to a medical appointment. After arriving, I parked near the valet station, turned off the car, and went inside to check in at LabCorp. Within two minutes, witnesses reported black smoke from the hood — followed by a violent explosion that shook the office building and triggered a multi-unit response from local fire and police departments. When I came downstairs, my vehicle was engulfed in flames. The front end was completely destroyed. Mercedes-Benz USA sent an investigator on September 8, 2025 to examine the wreck. Despite numerous follow-ups, I have received no written report, no findings, and no communication from Mercedes-Benz since that inspection detailing any relevant information. Safety Context: In March 2024, Mercedes-Benz issued Recall #24V-207, affecting 2019–2023 GLE and GLS models, citing a defective 48-volt ground connection that could cause a fire. My incident occurred in a GLS 450 model and appears consistent with this recall defect. If confirmed, this could indicate that the recall did not capture all affected VINs or that repairs were not properly executed. This incident was minutes from being fatal — and could easily have occurred on the highway or in my garage or with my 4 children inside. The lack of corporate response for over two months raises serious concerns about consumer safety, recall effectiveness, and corporate transparency.
We had our Mercedes GLS550 2017 with 59,295 overheat and call for immediate shut down on the Massachusetts Turnpike with my wife and child in the car. It was quite a dangerous situation because the failure caused by hose assembly 166-830-15-00 clamp (as described by the dealer as the reason for the loss of fluid and hose failure) caused almost an immediate overheating. The service advisor stated that it is "a quite common failure". I was quite suspicious, because just 11 days prior and 138 miles prior they had performed an Oil Change (Service B9), and thought their mechanic must have damaged the hose fitting they claimed broke. When I looked at the schematic, the fitting is quite close to the Oil Filter Cap, so I assumed that the mechanic accidentally knocked the plastic clamp and broke it. However, they said this was a "normal failure" on these cars. I am a data scientist and have requested failure rates for similar autos in the data cohorts of 50,000, to 60,000 miles and 4 to 5 years old. It woudl be also nice to see if there was data available that included Post B( service visits for the same failures. I was surprised they tracked this data since I was told it was a common failure of this part. Looking at the design of where the host runs, it is certainly exposed to a mechanics tools removing the Oil Filter wrench. If this is common, I would like to help other families with young children being stranded by the side of a busy highway. In this case, I told my wife to drive to the closest safe point even though the engine warning system said to stop immediately. The engine seems to survive fine. I dont know if you record other data on this type of hose assembly failure, but a redesign with non-plastic clamp might be more durable and more appropriate.
I DROVE UP AND DOWN THE WESTERN UNITED STATES ON HIGHWAYS AND CITY STREETS. I DROVE 16 HOURS A DAY FOR ABOUT 1 WEEK. I RECEIVED A CHECK ENGINE LIGHT WITH A WARNING THAT THERE WAS A SMALL EVAP LEAK. AFTER BEING SERVICED THIS WARNING DID NOT APPEAR AGAIN. I BELIEVE THE THRESHOLDS WERE UPDATED TO IGNORE SMALL EVAP LEAKS. AROUND OCTOBER 28, 2019, I NOTICED THE FLOOR BOARD OF MY VEHICLE OVERHEATING. I ALSO DETECTED MORE EXHAUST FUMES ENTERING THE CABIN. I BELIEVE THE CATALYTIC CONVERTERS ARE LESS EFFECTIVE AND A BLOCKAGE IS CAUSING MORE EXHAUST TO LEAK FROM THE EMISSIONS SYSTEM. HOWEVER NO CHECK ENGINE LIGHT WARNING SO THE MANUFACTURER WILL NOT REPAIR UNDER WARRANTY. I WAS INITIALLY GETTING HEADACHES AND EXPERIENCING PAIN IN MY SPINAL CORD. NOW I AM EXPERIENCING CHEST PAINS WHILE DRIVING.
Complaints are unverified consumer reports submitted to NHTSA. A high complaint count may reflect vehicle popularity, not defect severity. Data sourced from NHTSA public records.