Normal driving it sits around 145 -150. At highway speed (70mph+) only hits about 180. Never used to have this problem until they rebuilt the engine. I have replaced to thermostat twice with new OEM parts. No problems through the warmer months but keeps throwing a code saying it doesn’t get up...
I have 2015 ram, just put the second thermostat in it and it still won’t get up to normal temperature range. What else in the system could be causing that?