Welcome to FRF. There’s a lot of good information in this thread:
Things to look for on a test drive - Used 2017 Raptor
You want a cold start up; that is, the truck has sat overnight, or at least 12(?) hours to check for the cam phaser park failure. You’ll know it if you hear it at start up. If it is a private sale, ask if the cam phasers have been replaced and check paperwork if available.
If it has a moon roof, verify function before making any agreements. The track system is fragile and requires maintenance that is not well documented. A routine application of Ford’s “Krytox” grease keeps things quiet and moving freely.
If it’s lifted or leveled, check the CV boots.
Listen for IWE noise. in 2h, give it some good throttle from a start. you don’t need to floor it, just moderate to 3/4. get to at least 4th gear / windows down. listen for a rattling sound. This is usually a very inexpensive solenoid, but can be more - lines and if it’s been ignored it can cause more $$$ damage. if you hear the rattling, select 4a and retest. if the noise goes away, it’s an IWE problem.
Get underneath, check for leaks. some ’18 MY have the plastic oil pan, others have the metal pans. Some plastic pans leak, some don’t but Ford abandoned the plastic pan part year through ’18. If you see the plastic pan leaking, know that it’s an intricate repair that many stealerships seem to have trouble with, resulting in return visits and they will not fit the newer metal pan to a plastic pan truck.
check the oil level, there was an issue with oil consumption incident to a valve cover issue.
there have been some recalls - door latch freezing, seat belts and there’s a memo about the tailgate dropping - not sure if that’s inclusive of ’18’s but does affect 2017.
That’s all I can think of off the top of my head.
Good luck!
