Most common 2018 Mercedes-Benz GLS450 problems
Share of the 14 complaints; one complaint can involve more than one system. "~" is the median mileage when the problem started.
Mercedes-Benz GLS450 complaints by model year
Best GLS450 years: 2023, 2022. Years to avoid: 2020, 2024, 2021. Compare all years →
2018 Mercedes-Benz GLS450 recalls (3)
Communication › Auto crash notification
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2017-2022 CLA-Class, GLA-Class, GLE-Class, GLS-Class, SLC-Class, A-Class, AMG GT-Class, C-Class, E-Class, S-Class, SL-Class, GLC-Class, CLS-Class, GLB-Class, and G-Class vehicles. Please refer to MBUSA's recall report for specific vehicle model details.
Remedy: The communication module software will be updated through an Over-the-Air (OTA) update or by a dealer, free of charge. Owner notification letters were mailed July 8, 2022.
Communication › Auto crash notification
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2016 - 2021 CLA-Class, GLA-Class, GLE-Class, GLS-Class, SLC-Class, A-Class, GT-Class, C-Class, E-Class, S-Class, CLS-Class, SL-Class, B-Class, GLB-Class, GLC-Class, and G-Class vehicles. Please refer to the Part 573 report for specific vehicle model details.
Remedy: MBUSA will notify owners, and the communication module software will be updated by a dealer, or through an over-the-air (OTA) update, free of charge. The recall began March 12, 2021.
Service brakes, hydraulic
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2018 Mercedes-Benz GLE350 4Matic, GLE350, GLS450 4Matic, GLS550 4matic, GLE43 AMG 4Matic, GLE63 AMG 4Matic, GLE63S AMG 4Matic, and GLS63 AMG 4Matic vehicles.
Remedy: MBUSA will notify owners, and dealers will bleed the rear axle brake system, free of charge. The recall began September 14, 2018. Owners may contact MBUSA customer service at 1-800-367-6372.
What 2018 Mercedes-Benz GLS450 owners say
Suspension
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.
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.
Brakes
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. …
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 [redacted]
2018 Mercedes-Benz GLS450 engines & fuel economy
| Engine | Transmission | Drive | MPG city / hwy / combined |
|---|---|---|---|
| 3.0L 6-cyl turbo | 9-speed automatic | 4WD | 17 / 22 / 19 |
EPA ratings. Class: SUV.
Frequently asked questions
Is the 2018 Mercedes-Benz GLS450 a good car?
There isn't enough complaint history for the GLS450 to compare model years reliably. So far owners have filed 14 complaints with NHTSA.
What is the most common problem with the 2018 Mercedes-Benz GLS450?
The suspension — 3 complaints, 21% of all complaints for this model year. Next are the brakes (3) and electrical system (2).
How many recalls does the 2018 Mercedes-Benz GLS450 have?
There are 3 recalls for the 2018 Mercedes-Benz GLS450, the most recent from May 20, 2022 (auto crash notification). Recall repairs are free at any authorized dealer — check whether yours has been done with the VIN recall check.
What are the best and worst years of the Mercedes-Benz GLS450?
The best years by complaints, compared at the same age, are 2023 and 2022. Years to avoid or approach with caution: 2020, 2024 and 2021. See the full Mercedes-Benz GLS450 years comparison.
At what mileage do 2018 Mercedes-Benz GLS450 problems happen?
The median mileage reported in complaints is about 8,000 miles; 100% of problems with a recorded mileage started before 50,000 miles.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.