2012 Mercedes-Benz GLK350 Problems

What owners report

For this model year, the overwhelming majority of sampled complaints concern the Takata airbag inflator recalls: owners report long waits for replacement parts, mixed answers from dealers, and a few describe inflator or deployment incidents. Outside the airbag recalls, the pattern that repeats most is a fuel smell and fuel leak around the tank area after filling up, plus a smaller set of reports about a steering lock that prevents starting and rear brake or subframe corrosion found on higher-mileage cars.

1. 1
   Air bags

   Airbag recall parts unavailable (Takata inflators)

   • 128 complaints (77%)
   • median 46,000 mi at 4.6 yrs old (10 state mileage)
   • 2 mention a crash, fire or injury
   • filed 2016–2026

   Owners describe receiving recall notices for the driver and passenger frontal airbag inflators, then being told the remedy parts are not available. Complaints describe repeated dealer and manufacturer calls over many months or years, and in some cases being told the car was dropped in repair priority or that a loaner would not be provided. A few describe warning lights or airbag-related deployment events, including an incident where other airbags did not deploy in a crash. Reported across a wide mileage range, mostly between roughly 20,000 and 80,000 miles, and largely in complaints filed from 2016 onward.

   Recall 19V010000Recall 17V017000Recall 16V0810002 related service bulletins

   What to check: Ask the dealer to run the VIN and confirm whether the driver and passenger inflator recalls have been completed, and get that in writing; an open recall may still be waiting on parts. Also check whether the airbag warning light stays off after the self-test on startup.

   2 excerpts from owner complaints in NHTSA records

   “Takata recall we were notified of this recall nearly three years ago. There has been no movement on a repair. This is absurd, we have actually been notified that our two mercedes vehicles that are affected by this recall, have been dropped in priority for a repair.”

   NHTSA complaint #11175230, filed 2019-02, 45,000 miles

   “After just parking the vehicle but before getting out - the drivers headrest exploded and pushed my head toward the steering wheel. When driving the vehicle home the message center said problem with the driver front airbag and the passenger front airbag and the warning light was on. The next day I drove to the dealer and they pushed the headrest back together but could not get the message removed and said it would need diagnostics. I drove away with the messages still coming on intending to make an appointment for diagnostics. …”

   NHTSA complaint #10855155, filed 2016-04, 105,000 miles
2. 2
   Fuel system

   Fuel smell or leak around the tank after filling up

   • 13 complaints (8%)
   • median 75,000 mi at 6.7 yrs old (3 state mileage, few)
   • filed 2017–2024

   Owners report a strong gasoline smell inside the cabin and outside the car every time the tank is filled, often fading as the fuel level drops. Some describe fuel dripping on the ground or onto covers under the rear of the vehicle, and a few mention that topping off makes it worse. Complaints describe dealers answering that the evaporative system is working normally, that the VIN is not covered by the fuel-system recall, or quoting a diagnostic fee; some owners paid for repairs themselves. Typically reported after fill-ups at any mileage, appearing in complaints from roughly 38,000 to 120,000 miles.

   Recall 12V5570001 related service bulletin

   What to check: Fill the tank during the test drive and then check for a fuel smell in the cabin and for drips under the rear of the car, and ask whether the fuel filter flange recall (12V557000) was performed on this VIN.

   2 excerpts from owner complaints in NHTSA records

   “The glk smells like gas any time it's fueled up. I never top it off because if I do, it leaks fuel until I get down to 3/4 of a tank. I took it in to get looked at and the dealership warranty dept. Told me my VIN number was not one of the ones affected by the sameexat type of fuel leak as others in the recall! I am sorry that I ever bought this vehicle, I will never buy Mercedes-Benz again1”

   NHTSA complaint #11119889, filed 2018-08, 75,000 miles

   “Since new the glk would smell like gas any time you fueled up. I never topped it off because the dealer told me that may be a reason you smell the fuel. I took it in to get looked at an they told me it's common it's just the evap system working. That's fine but after a few years anytime I filled up I noticed it would start leaking onto my garage floor. I took it in to the dealer and they told me it's out of warranty by a month an this would cost over a thousand to get fixed. …”

   NHTSA complaint #11101947, filed 2018-06, 38,000 miles
3. 3
   Brakes

   Rusted rear brake lines and rear subframe corrosion

   • 11 complaints (7%)
   • median 79,000 mi at 8.0 yrs old (2 state mileage, few)
   • filed 2017–2025

   Owners describe brake lines rupturing without warning while driving, and rear subframe corrosion extensive enough that the car was judged unfit to drive. Complaints describe a dealer covering the rear subframe under an extended warranty while the brake lines were not covered, and one owner reports a repair estimate in the thousands. Others report a vibration or grinding felt while braking or driving. Reported on older, higher-mileage cars, generally in complaints filed after 100,000 miles or around a decade of use.

   1 related service bulletin

   What to check: Have the car inspected from below on a lift, specifically the rear subframe and the metal brake lines for rust, and ask whether the rear subframe extended warranty applies to this VIN.

   2 excerpts from owner complaints in NHTSA records

   “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.”

   NHTSA complaint #11607686, filed 2024-08

   “I brought my car in to my local mechanic and was told my rear suspension was corroded. He said it would cost around five thousand dollars to repair. I researched online and found mercedes did not have a recall but has extended the warranty and will cover the repair to the rear suspension. The mercedes dealer called me and told me my brake lines were rusted out and needed replacement and that it was not covered by the extended warranty and would cost thirty five hundred dollars. …”

   NHTSA complaint #11701710, filed 2025-11

Buying note. Check recall status by VIN first, since airbag inflator parts have been slow to arrive for this model year, then budget for a pre-purchase inspection that includes the fuel tank area and the rear brake lines and subframe. Service records showing whether the fuel-system recall and any steering-lock work were done are worth asking for.

Summary written with AI from a sample of 60 NHTSA complaints for this model year (picked at random, with complaints that state a mileage and recent ones taken first), then checked automatically against the source records. Where a problem shows a complaint count, every complaint for this model year was matched with fixed keyword rules (written with AI and tested against the sample), and the mileage, age and repair figures are calculated from those complaints; owners' figures are as stated, not verified. Other counts refer to the sample. The excerpts come from NHTSA's public complaint records and are unverified; capitalisation is normalised, NHTSA staff notes are removed, and shortened text ends with “…”. Something wrong? Request a correction.