95 2.3L, last winter she started taking a long time to get warm. It sucked, especially in some of the sub-zero Michigan mornings we had. I was a cold dude. I figured the old thermostat was stuck open, so I wasn't too worried about it. What with a long Labor Day weekend and all, I figured I would change the oil and the fluid in the diff, and while I was at it I'd pop in a new thermostat. I pulled out the old one, didn't appear to be stuck open. Well, after putting it all back together once, I discovered that the housing was shot. Picked up a new housing, managed to bust the sensor trying to get it out. New sensor, and upper radiator hose went on the second time. Doesn't appear to be leaking, but I'm also noticing that the truck is still taking a long time to warm up. When I burped the cooling system, it seemed like the upper radiator hose started to get warm pretty much right away, unlike the other times I've done thermostats. I'm curious what other possible causes there are for this.
As always, any and all help is greatly appreciated.
Thanks,
Art

 

A long time for the temp gauge to show warm, or a long time before heater starts blowing warm ?

 

Upper radiator hose should not start to get warm until engine temp is above 190degF, t-stat should be 192 or 195degF model

If its heating up then t-stat is leaking, the "jiggle" valve will let some warm coolant flow out but not much, feel heater hose to compare, that should get HOT as engine warms up

Also test fan clutch
When engine has been sitting overnight open the hood and try to spin fan blade, should be "cold locked" so hard to spin

Start engine and run it for 20-30 second then shut engine off
Try to spin fan again, should spin easily, its unlocked now

If its still hard to spin then it "locked" all the time, this will cause the 2.3l Lima to never warm up in the winter