Most common 2012 Mercedes-Benz GLK350 problems
Share of the 167 complaints; one complaint can involve more than one system. "~" is the median mileage when the problem started.
Mercedes-Benz GLK350 complaints by model year
Best GLK350 years: 2007, 2014. Years to avoid: 2010. Compare all years →
2012 Mercedes-Benz GLK350 recalls (4)
Air bags › Frontal › Passenger side › Inflator module
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2014 C250, C300 4Matic, C350, C63 AMG, E350 4Matic Coupe, E350 Cabrio, E350 Coupe, SLS AMG Cabrio, SLS AMG Coupe, 2014-2015 C250 Coupe, C350 4Matic Coupe, C350 Coupe, C63 AMG Coupe, GLK 350, GLK250 BlueTec 4Matic, GLK350 RWD, 2015-2017 E400 4Matic Coupe, E400 Cabrio, E400…
Remedy: MBUSA will notify owners, and dealers will replace the passenger frontal air bag module, free of charge. The recall began March 29, 2019. Owners may contact MBUSA customer service at 1-800-367-6372.
Air bags › Frontal › Passenger side › Inflator module
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2012 C300 4Matic, C250, C250 Coupe, C350, C350 Coupe 4Matic, C350 Coupe, C63 AMG, C63 AMG Coupe, E350 Coupe 4Matic, E350 Cabrio, E350 Coupe, E550 Cabrio, E550 Coupe, GLK350 4Matic, GLK350, SLS AMG Cabrio, and SLS AMG Coupe vehicles originally sold, or ever registered, in…
Remedy: MBUSA will notify owners, and dealers will replace the front passenger air bag modules, free of charge. Owners were sent an interim notification in March 2017.
Air bags › Frontal › Driver side › Inflator module
Mercedes-Benz USA, LLC. (MBUSA) is recalling certain model year 2009-2010 ML320 BlueTec 4Matic, GL320 BlueTec 4Matic and R320 CDI 4Matic, 2011 E350 Cabriolet and E550 Cabriolet, 2009-2011 ML350, ML350 4Matic, ML550 4Matic, ML63 AMG, and C63 AMG, 2010-2011 ML450 4Matic Hybrid, E350 Coupe, E350 4Matic, E550 Coupe, E550 4Matic,…
Remedy: MBUSA will their notify owners, and Fiat Chrysler will notify the affected Chrysler owners. Dealers for the respective brands will replace the driver's frontal air bag module, free of charge.
Fuel system, gasoline
Mercedes-Benz is recalling certain model year 2011-2012 S400, S550, S550 4Matic, S63 AMG, C300, C300 4Matic, E350, GLK350, GLK350 4Matic, CL550 4Matic, and CL63 AMG vehicles manufactured from April 18, 2011, through July 12, 2011.
Remedy: Mercedes-Benz will notify owners, and dealers will replace the fuel filter, free of charge. The recall campaign is expected to begin in February 2013. Owners may contact Mercedes-Benz at 1-800-367-6372.
NHTSA defect investigations
Federal safety investigators have looked into a possible defect involving the 2012 Mercedes-Benz GLK350:
Desiccated Air Bag Inflator Rupture
From 2000 through 2017, Takata produced millions of air bag inflators using two types of phase-stabilized ammonium nitrate ("PSAN") propellant -- propellant 2004 and propellant 2004L. After prolonged exposure to high temperature cycles and humidity, inflators using propellant 2004 can degrade, causing the propellant to burn too quickly when ignited.
What 2012 Mercedes-Benz GLK350 owners say
Air bags all 132 →
On August 17, 2025 I rearended a vehicle in front of me who jammed on their brakes for no apparent reason. We were the only two vehicles in the area. Upon impact, the following airbags deployed....steering wheel, driver knee airbag. I sustained injuries to my lower extremities from the exploded knee airbag which contained metal components that impaled my skin. I continue to receive treatment for multiple injuries and the wounds that have not healed. My safety was at risk due to the metal components (shrapnel) deployed via the exploded knee airbag. I also sustained injuries my left wrist from the steering wheel airbag, and my left chest from the tightening of the seatbelt. The local Mercedes Benz dealer recently towed the vehicle from my home address to their facility for inspection of said airbags. As of today, I have not received any report from MBUSA.
The component or system failed or malfunctioned: Brake pedal -does not brake effectively Engine :Alternator/ignition-the car would not start on me Cigarette lighter: front cigarette lighter does not work (greater fuse or electrical problem Inspection: Car was returned to Hawthorne Auto Square for repair and ultimately returned and sale of the used car was cancelled due to these issues. Please inspect car at Hawthorne Auto Square 11646 Prairie Ave, Hawthorne, CA 90250. Please do not allow Hawthorne Auto Square to resell this car it is a hazard to all Safety of myself and others were put at risk: - when attempting to brake, the car does not stop in a safe distance (dangerous can cause car crash) ( this happens to many GLK 250s) -the car is not starting after being started(dangerous if driving and cuts off in traffic and causes accident) air bag disabled -light coming on in car( if airbags …
Fuel & propulsion system
The contact owns a 2012 Mercedes-Benz GLK350. The contact stated that the vehicle was leaking fuel underneath the rear-end of the vehicle. The failure occurred intermittently; however, the leak was now more frequent. The contact took the vehicle to a certified mechanic who diagnosed and related the failure to NHTSA Campaign Number: 12V557000 (Fuel System, Gasoline) however, the VIN was not included. The vehicle had not been repaired. The manufacturer was made aware of the failure. The approximate failure mileage was 120,000.
My 2012 GLK350 leaking gas from under the rear right passenger seat, where the gas cap located. we fill up gas when we came back to home and park in the garage gas smell was very strong We thought may be because of spill some gas while Pumping. Next day gas smell was still strong inside of garage. I found gas leaking from under the rear right passenger seat. gas was dripping on the plastic cover Panel. I started google to find out what is the problem. Then I found NHTSA recall document #12V-557 regarding this problem, the Document specifically indicate and explained about faulty fuel filter flange might crack to leak gas fuel.it stated certain Model Year 2011-2012 GLK350.So I went House of import MB dealer service advisor [redacted] inspected car briefly then he checked MB recall status of my car. …
Brakes
My rear subframe is rotted out but won't be replaced under warranty because there are no rust holes in the metal. The rust is very extensive, and the car isn't safe to drive. The rear metal brake lines are also rotten and need to be replaced. I've owned many cars older than this one with more miles, and I've never had rusted-out brake lines. This is a safety issue.
The component or system failed or malfunctioned: Brake pedal -does not brake effectively Engine :Alternator/ignition-the car would not start on me Cigarette lighter: front cigarette lighter does not work (greater fuse or electrical problem Inspection: Car was returned to Hawthorne Auto Square for repair and ultimately returned and sale of the used car was cancelled due to these issues. Please inspect car at Hawthorne Auto Square 11646 Prairie Ave, Hawthorne, CA 90250. Please do not allow Hawthorne Auto Square to resell this car it is a hazard to all Safety of myself and others were put at risk: - when attempting to brake, the car does not stop in a safe distance (dangerous can cause car crash) ( this happens to many GLK 250s) -the car is not starting after being started(dangerous if driving and cuts off in traffic and causes accident) air bag disabled -light coming on in car( if airbags …
2012 Mercedes-Benz GLK350 engines & fuel economy
| Engine | Transmission | Drive | MPG city / hwy / combined |
|---|---|---|---|
| 3.5L 6-cyl | 7-speed automatic | RWD | 16 / 22 / 18 |
EPA ratings. Class: SUV.
Frequently asked questions
Is the 2012 Mercedes-Benz GLK350 a good car?
Based on 167 owner complaints filed with NHTSA, the 2012 GLK350 rates average: 1.4× as many complaints as a typical year of the GLK350 at the same age. Complaint counts don't account for sales volume or individual maintenance, so have any used car inspected before buying.
What is the most common problem with the 2012 Mercedes-Benz GLK350?
The air bags — 132 complaints, 79% of all complaints for this model year, most often about frontal. Next are the fuel & propulsion system (13) and brakes (6).
How many recalls does the 2012 Mercedes-Benz GLK350 have?
There are 4 recalls for the 2012 Mercedes-Benz GLK350, the most recent from January 9, 2019 (inflator module). 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 GLK350?
The best years by complaints, compared at the same age, are 2007 and 2014. Years to avoid or approach with caution: 2010. See the full Mercedes-Benz GLK350 years comparison.
At what mileage do 2012 Mercedes-Benz GLK350 problems happen?
The median mileage reported in complaints is about 45,000 miles; 59% 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.