I have a home in rust free Florida. I also have a temporary place in PA. Quite simply, I'm shocked at how awful (and how physically noisy) the road salt/sand/brine thing is up North. My rust free Jaguar has been up in PA for 3 months and all of the underside components are rusting. Just like that, the emergency brake seized up, the caliper bolts are rusting in place and so on. 3 months!!
Living up North comes at a price. That price includes spending money (and/or effort) on heating your homes and businesses, followed closely by additional automotive expenses in the form of winter crashes, winter tires, lower fuel economy and shorter vehicle life/higher maintenance due to rust.
With that in mind, your vehicle is worth market value, which unfortunately is much less than you'd like. (again, due to the above)
If you can't trade it in, sell it for what ever the market will bear.
However, in this case, since it's starting to have a mechanical issue, a trade in is a way avoid future trouble.
I don't know what oil you chose and what your OCI's were. But one thing is clear, despite the long OCI push here at BITOG and the related good UOA results. Timing and balancer chains, along with low tension piston rings, wear and fail rather quickly with uber thin, micro particulate contaminated oil. Oil changes are the only way to remove those particulates. Choose a quality synthetic of sufficient viscosity and change it frequently. Your engine is known to reach 300,000 miles with proper treatment.
My 3.5 Ecoboost gets a diet of 10W-30 M1 EP. WIth 5000 mile OCI's. AND in my case, 5000 miles is 1000 miles TOO LONG. The oil is contaminated with fuel by 4000 miles. Remember, that fuel evaporates, leaving behind fuel residue that IS NOT OIL. But my method is to change oil at the 5's. So 75,000 miles, 80,000 miles, 85,000 miles and so on. Easy and works on nearly any vehicle.