Yea, your lower hose is the coldest spot in the system and will stay cold to the touch for about 10-15 minutes roughly, when the thermostat opens there's a noticeable change. How did you bleed the coolant, with the rad cap off and with a radiator funnel? That is the only way to go because fsm's method of keeping it sealed takes a lot of time. I think you have air still trapped especially in your core, so I suggest using a funnel($20), the alternate is draining a little over a quart of coolant from the rad drain and run it.
I didn't think it was possible to put the thermostat in wrong but I know that gasket has to be good.
BTW, I've heard of OE Toyota boxed thermostats going bad right out of the box so thermostat failure isn't completely out of the question. I just think you still have air in there, especially if the fans never come on(which takes a long time to do at idle on cold startup).
'02 IS300 MSM LSD
Last edited by jasonm4; 05-14-2014 at 04:41 PM.