This is super weird! I actually just replaced my thermostat and water pump less than a year ago. How should I check to see if they're bad ?

I just got the car up on jack stands, and just had a realization, my car went into limp mode a while back and I took out the servo motor gear and rotated it 180 degrees and re installed it. I have a feeling this temporary solution I had a while back might be failing again now.