So, after swapping the viscous fan, fixing my valve cover gasket and re bleeding the coolant system I'm still having overheating issues. I idled for 30 some minutes with no issue, temp hit 199 at its highest after 30 minutes or so but it idled much higher than it had before. About 1500 rpms. I figured it was good to go but after 30 minutes of driving on road temp started climbing. About 200-210. Then after about 30 minutes of mild offroading I saw peak temp of 219 so I shut it down for a while and drove it back home. I am in Nevada so its pretty hot this time of year but I feel like my temps should still never get this high.

To replace the valve cover gasket I disconnected the lower rad hose, the two coolant hoses above the passengers side valve cover, the fuel lines above the cover, and the pcv line.

my two questions are: 1.) what could be causing my high idle.
2.) what could be affecting my temp at road speed if it seems to idle alright


1997 D1, 4.0 V8, 175k, automatic, 2 inch lift

 

Following.
I have almost the exact issue cept for high idle.
Radiator is the only part yet to be addressed. Your rad?

 

My radiator is fairly new, and all coolant that comes out is very clean so I don’t think it’s the rad I’m thinking thermostat might help