When I first got Rubie Sue, she was very cold blooded, took forever to warm up. And she really ran crappy when cold.
So, I swapped out the thermostat, problem solved. She now is heated up by the time I get to work; used to be still cold. I suppose I could have tested it first, but it was cheap enough, and easy enough to swap out. I used a new gasket when replacing it.
Cheap easy fix. She's slowly coming around to running better. Not too much more to go.