NHTSA Complaint #11660562 — 2021 MERCEDES-BENZ AMG GLB35

On 4/13/25 while driving my car on the highway, along with my 2 young children, I began to hear what initally sounded like a "flapping" noise. I rolled the windows down and after a minute or 2 the sound got lounder. There was never a warning or any type of safety icon that appeared on the control panel, nor any driving performance issue before hand. Shortly after the initial noise I could tell the car was struggling to accelerate. I wasn't near an exit during this time and began to panic in fear the car would shut down and I had no safe place to pull over on that stretch of highway. The noise turned into a banging within another min or so and I finally noticed an exit up ahead. Almost immediately as I excited the highway, the car completely shut down with me having practically no control of the steering wheel and unable to put the car into neutral. I coasted to the stop sign at the end of the exit ramp. The car would not restart after 2 attempts, I stepped out to see a massive amount of oil coming from under the car. The car recently had the 4th cylinder head replaced in Jan 2025 and was in the shop for almost 1 month. I was assured the engine was safe to drive after that repair. It has remained unserviced at the dealership since 4/13/25 and was informed it has catastrophic engine failure due to a thrown rod with Cylinder 2 being the "source of the failure." The dealership has quoted a $28k+ repair bill and Mercedes corporate has refused to replace it with a "goodwill" gesture. Only offering $1,500 toward repairs and no reimbursement for any of the 4 rental cars Ive obtained since my vehicle has been inoperable. I was not informed at the time of my purchase about any defects on the M260 engines faulty cylinder head & Mercedes extending a warrenty due to such. They are refusing to accept liability for the cacade of damage & ultimate engine failure steming from now cylinder 2. This event risked the lives of my children's and myself due to Mercedes negligence.