I did my water pump a while ago and ever sense my temp sensor sometimes reads cool/cold. Sometimes it will just be a little on the cool side, other times it will read almost completely cold then it goes back to normal. Never reads hot. Runs totally fine otherwise.

I've done everything I know of to remove air from the system, could I just need a new thermostat?

 

Could be thermostat. Could be a damaged wire at the connector for the sender. Could also be a bad sender.
I thought my sender was bad and when i was replacing it I found the wire was damaged. Fixed that and replaced the sender and it's been good.

 

Ok cool so whats a sender?

 

The sender is what tells the gauge what to read. The sensor is what the computer uses for temperature.

In a nut shell...
Sender = gauge
Sensor = ECM

 

https://smile.amazon.com/Motorcraft-...dp/B000C5FSLO/

Why is this $126!? Whats the 2nd best option because all the others don't have the same temperature rating?

 

That comes with everything. I'm not too familiar with the 2.3L but I do know they have some wierd issues.

 

Thermostats on the 2.3 are known for this. The legs that hold the thermostat in the water neck tend to break off and cause the thermostat to stay open, which results in the cooler reading on the gauge. Buy the Amazon part, it's cheaper than the parts stores. lol.