SUSPENSION07/06/2026
The contact owns a 2018 Mercedes-Benz GLS 550. The contact stated while driving at various speeds, the vehicle made an abnormal clicking sound when making a right turn, and an abnormal ticking sound at startup. There was no warning light illuminated. Another driver informed the contact that the front passenger-side wheel was loose and followed the contact to the residence. The vehicle was taken to a local dealer, where it was diagnosed that the sway bar needed to be replaced; however, the sway bar was only adjusted. The contact stated that the failure had recurred. The dealer was notified and informed the contact that the vehicle was safe to drive. The manufacturer was contacted and advised that any additional repairs would be at the owner's expense. The contact was referred to the NHTSA Hotline for assistance. The failure mileage was approximately 75,045.
SERVICE BRAKES,ENGINE,FORWARD COLLISION AVOIDANCEfire12/05/2025
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 at right cylinder head. Coolant warnings and overheating despite adequate coolant. Radiator and vent line issues. Active Brake Assist Limited warning appeared. Late November - Vehicle emitted smoke and experienced a small engine fire, observed under hood after stopping. Mercedes dealership deemed car unsafe to drive. During engine replacement wood pieces were found where destroyed motor mounts should have been. Multiple issues with no notice or warning lights.
SERVICE BRAKES,FUEL/PROPULSION SYSTEM08/26/2025
Brake brakes are terrible. They have other years that they’ve 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 doesn’t 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)
SUSPENSION04/22/2025
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.
SUSPENSION04/14/2025
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.
UNKNOWN OR OTHER,VISIBILITY/WIPER03/10/2024
Water collects at the front row floor at driver and passenger sides
UNKNOWN OR OTHER12/31/2023
UNKNOWN
SEATS12/27/2022
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 cost of repairing this safety issue. The dealer says the cost for this repair is 1750.00. We are worried that if we have a passenger in the third row seat, they may be injured due to seat not locking. I believe this is a widespread safety issue and I believe it should be covered under a voluntary recall. INFORMATION Redacted PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6).
STRUCTURE,UNKNOWN OR OTHER03/21/2022
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 repair done on my own. Mercedes Benz of Walnut Creek, CA has inspected the vehicle and we're in the process of having the claim approved through my insurance. Completely unacceptable that this would happen on this (or any other vehicle). There is a class-action lawsuit against Mercedes for this exact same problem across a number of their models, so this is not an isolated incident. Had my wife been driving, she could have been startled to the point of losing control of the vehicle, possibly causing serious injury or death.
SERVICE BRAKES10/21/2021
Took vechicle for warranty repair of the frozen and suck both front calipers to Rallye mercedes dealer, repair was refused, car was noty drivable since brakes were stuck, still was kicked out of the dealership
ENGINEfire10/14/2021
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.
SERVICE BRAKES, AIR08/19/2021
The contact owns a 2018 Mercedes Benz GLS550. The contact stated that when the brake pedal was depressed there was an abnormal noise detected. The brake warning indicator light was illuminated. The contact stated that the brake pad on one side of the disc was completely worn, and the other side of the disc was like new with a full thick pad. The vehicle was taken to the local dealer and the contact was informed that the brake rotor needed to be replaced. The vehicle was repaired. The manufacturer was notified of the failure however, no further assistance was provided. The failure mileage was approximately 4,500. Consumer stated problem lies with the unevenness of the brake pad on both sides of the front wheels.
Showing 12 of 22 complaints.