NHTSA Complaint #11610296 — 2018 FORD F-150

I bought vehicle at almost 60,000 miles and 8 to 9000 miles later engine is misfiring. Vehicle has been in should previous year and I got it back this June(24) for 2 days and back in shop only to find that ford had work on cyclometer before and refuse to let that be know when it was in shop the first time from same noise and complaint. The dealer recommendation is for a new motor in which cost $12000 more on top of what I owe on truck and ford is refusing to fix the problems stating it’s out of warranty but they previously worked on vehicle. This vehicle had currently 70,000 miles on it and it should not be up for a new motor and I’ve only experienced this vehicle for 9 to 10,000 miles. Seems as if this was a patch up job on a lemon to be sold off and transferring responsibility of repairs to buyer. This is not right and I’m at a standstill on decision of how to proceed forward with situation.