So today I put a transsmission cooler on my 98 F 150 5.4, Took the lower tanny line from the rad put it into the cooler and back out to the lower line (return line ) to the back of the tanny E4OD, so then I decided to change the thermosat and rad fluid, so I drain the rad put some prestone flush crap in there and fill It with water, ran It for like 20 min, Didn't seem to be getting to warm, although the temp gauge said it was, and yes the defroster was on high with heat blowing out of it, the top rad hose seemed not warm ( you could hold your hand on it) so I thought to change the thermostat To the new one thinking Its not working properly, still the same thing, So WTF? I think is the rad plugged up or what ?? does it need a pressure flush? or a bomb?

Any suggestions ?

 

Sounds like it is operating optimally. Some cars get real hot at OT, and some don't. If the thermostat wasn't working, you'd know about it relatively quickly

 

Haaa I'm a retardI had air in the upper hose got it out works good now