On the way to work, here in Texas, I noticed the water temp was really low, about 150* I guess, and about 10 minutes later the check engine light came on.
Got to work and the radiator is full, no visable leaks.
The coolant resevior was low but i pulled the dip stick and the oil is clean and the correct color.
The t-stat is a fail safe type so if it fails it fails open to prevent overheating.
I can pull the code when I get home tonight but the question is this, if the t-stat is stuck open could it cause the truck to run that cold?
Has anyone had this situation happen before?
Thanks for your input.

 

Yes. Absolutely. I've had it happen a couple of times.

 

Definitely t stat. Get yourself a normal t stat. Most luck I've had with the fail safety ones is that they fail too soon, then you're fixing it again, and again....

 

Yep, the fail-safe stats suck. They fail all to quickly. Just putting a good quality (stant) thermostat in there is your best bet.