Hi. New here so be nice!
This 00 Rodeo has been getting up to 230° while traveling down the road. If I pull over and just idle the temp starts dropping immediately to 210° .
It takes quite a while to heat up so I replaced the t-stat then noticed the condenser fan wasn't running at high temp and found the ac needing a charge which activated the pressure switch which in turn activated the fan. Thought the problem would be solved but it still heats up to 230° going down the road.
Now I'm thinking water pump or very tiny leak in head gasket. Any ideas? Thanks

 

I know this is almost a year later... But I had the same issue with my 99 trooper. Turns out my clutch fan wasn't engaging on high temps. It seemed to be fine when cold but when the silicone oil inside it heated up, it just free wheeled. I fixed it by cracking it open and adding some Lucas oil stop leak, it's nice and thick like honey so it was similar to the silicone oil.
Works perfectly now

Edward.