My 93 Ford Ranger is losing power when I hit 5th
gear my thermostat gauge is fluctuating from cold
to normal too hot and then back down to cold and I
hear a thumping sound coming from my Dash area
from the passenger side is there something going
on that I'm mistaking
That sounds like a bad thermostat. It gets stuck closed until enough pressure builds up and then it opens, the engine cools and then it slams shut again.
The power loss might be related to overheating or maybe you just need a tuneup.