*Median odometer reading when the problem happened, where owners gave one. One complaint can name several problem areas.
EngineFire
January 2023 - Airbag suspension failed. Replaced by Mercedes dealership. December 2024 - Airbag suspension failed. Replaced by Mercedes dealership. April 2024: First brake failure. The brakes stopped while driving. Repaired. April 2025: Second brake failure. Brakes failed again. Repaired. The mechanic stated the line was too close to the wheelbase, resulting in a pinpoint-sized hole. No warning lights. July 2025: Engine failure - the vehicle experienced a complete shutdown while driving with no warning lights. Vehicle in shop for 6-8 weeks for engine replacement by certified Mercedes mechanic. Post-engine replacement (July - Nov 2025) - Severe oil leaks at left cylinder head, small leaks…
Dec 4, 2025Service brakes
Brake brakes are terrible. They have other years that theyâve acknowledge that the break are spongy and at times does not break the GLS has that defect. Also smell of gas fumes inside the vehicle. Please direct me the right way and help me with this issue. The brake issue almost have caused me two major accidents car doesnât stop mechanic says this is a Mercedes issue You may contact me at [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Aug 11, 2025Suspension
When attempting to rise/lower the automatic suspension, the compressor cooling notification pops up, followed by a malfunction. After this occurs, the vehicle is incredibly bumpy, to the point of it being unsafe to drive. The vehicle has been repaired twice already by the dealership under extended warranty and the condition has occurred a third time in less than three weeks. This is our family vehicle, and we cannot drive it due to the risk of shaken baby syndrome for our infant because of how much it bumps. Videos are available to show just how bad it is.
Apr 1, 2025Suspension
This 2018 gls 450 has issues with suspension system. Bought this car in 2023 and using since Jna 2023 and suspension system failed like 3 -4 times. Mechanic changed the air compressor , valves and others and still the car has same issue. It used to lift the car to adequate height but the compressor keeps on pushing it to cause teh compressor to fail.
Apr 14, 2025Seats
Third row seat will not lock. Warning message came on several months ago. I brought the vehicle in for service in may of 2022 to Mercedes Benz of Westwood MA. They neglected to repair the issue with the seat and returned the car back to me with the safety issue still unresolved. I spoke with the dealer and Mercedes Benz USA and they refuse to repair the vehicle under warranty even though it was still covered under the factory warranty. [XXX], the service manager at the dealership informed me that the third row seat motor needs to be replaced in order for the seat to lock. He said it is a very common problem with my model vehicle and that is the reason why the manufacturer wont cover the…
May 1, 2022Unknown or other
While driving our 2018 Mercedes GLS 450 down Highway 80 just outside Sacramento, CA, the stationary glass panel of our panoramic sunroof spontaneously explpoded. There was no impact by any outside force, it just shattered with the sound similar to a gunshot. Fortunately I did not lose control of the vehicle, and thankfully the sun shade was closed otherwise broken glass would have showered down into my vehicle. this happened in early evening (around 7:00PM and the ambient temperature was 66 degrees outside, so this had nothing to do with temperature either. Mercedes Benz told me that since I am 3 months outside of warranty they would do nothing to help us and I would need to have this…
Mar 5, 2022EngineFire
The contact owned a 2018 Mercedes Benz GLS450. The contact stated that after turning the ignition switch off, the driver suddenly discovered flames were coming from the engine compartment. The fire department was called to the scene and extinguished the flames. During the incident, the vehicle was destroyed and later towed away. A fire report was taken at the scene. The cause of the failure was not determined. The manufacturer and local dealer were notified of the failure. The VIN was not available. The failure mileage was 15,000.
Jul 15, 2019 · 15,000 milesStructure › Body
PART OF MY PANORAMIC SUNROOF SPONTANEOUSLY SHATTERED WHILE SITTING AT A STOPLIGHT. THERE WERE NO CARS OR TREES AROUND AT THE TIME. NOTHING TOUCHED THE CAR WHEN IT HAPPENED.
Jan 6, 2021 · 22,689 miles
Owner complaints are submitted to NHTSA by the public and are not verified. Shown as filed (NHTSA removes personal details); long reports are shortened.