on my 3.8 NA
i noticed the temp gauge wasnt going up as normal. (i did replace the thermostat last night just to be sure)
after driving 20 or so miles my low coolant light came on so i checked it was low maybe a cup worth low. but the upper radiator hose was warm and the lower was way way cooler, I know a radiator is suppose to cool the coolant but it seemed way to cold. after replacing the thermostat it gets to temp way faster. my next thing is going to change the coolant elbows prolly this weekend. gotta get it done before christmas driving..