just aquired this truck, runs great. Previous owner said people he got it from converted it to high flow. Issue is it wont get over 135-140 EVER! start up and idling it will barely get over 100. Replaced thermostat no change , fan/clutch working fine. It works (tested) but of course it never comes on. I am at a loss, how do i get this thing to heat up? Radiator has 2-1/2" upper and lower hoses and is a horizontal aluminum radiator. Thermostat housing is for single barrel type stat with 2" outlet to top rad hose and 1-3/4" cross connection hose. I know most complain ablout OVER heating, hell I want it to get hot LOL
When you replaced thermostat, did you replace the lip seal down in the housing the stat runs against?
My own first thought.
Can you attach pics? It sounds like you have a bypass t-stat stuck open. Does this have a charged air cooler or an aftercooler?
That is actual temp and not what a dash gauge is showing?