I've had my Raptor for two years. I am up to date on all my services. My last service/ oil change was 900 miles ago. I noticed a knocking noise on the way to work and called Ford service when they opened. They asked if any warning or service lights we're on, which none came on. I made an appointment to bring it in as soon as I got off work, the same day. I drove straight to dealership after work, as I pulled in the motor was still knocking. The service tech asked me what was wrong, I said I'll show you and started my Raptor, there was a loud knocking noise and the truck died. The engine locked up, dead. The service representative checked my oil and said there was no oil in the truck. At that time he searched for evidence of a leak, but could not find one. There was no evidence of burning oil via exhaust. The next day upon further inspection, no evidence of any leak can be found. All my services have been done at a Ford dealership. Initially I was told, since there was no oil in the truck, it was negligence on my part; therefore, the engine would not be covered under warranty. The dealership is dissecting my engine to see if they can find any reason why my Raptor lost 5 quarts of oil in 900 miles and hopefully a reason to warrenty a motor. Once again no warning or service lights ever came on. My truck has been in a ford service center for 3 days and no hope in sight. The dealership recommended I file a customer service complaint to start a case file and investigation, which I have. Has anyone ever had or heard of an issue like this or any idea how the oil could have been lost? Can anyone possibly shed any light on my trucks demise? Thank you, Sedator13