2001 Ford Crown Victoria PPV 4.6L V8 Automatic w/ 167,452 Miles

I just bought this off a government lot, and when driving, it runs fine up until about 30-40 miles per hour, sometimes it varies between 50 and 40. I notice that it revs high but does not shift past 3rd gear and causes me to slow down and ending up having to shift into second to get it moving. I took it to a few friends who said it might be a solenoid in the transmission, there's no weird noises other than an obnoxious whine during the revs in 3rd gear. There is no check engine light and I have checked the Transmission fluid and it is new and full, what could be causing the issue if not the solenoids?