6161, mine is doing the same thing right now....Picked up another t-stat, gonna change it out tom...hopefully its just a bad t-stat. A lot of things are out the box bad these days....Hope you get it figured out and let us know what you came up with.
Just got out of the shop, had them put a new thermostat in under warranty. Took it for a test drive and it is still running at 172 degrees and when it idles it drops to 150 degrees. Took it back and they said that it is supposed to run at 170 degrees with no load so there was nothing wrong with it and it should have never been running at 190 degrees. Is this true? What temp does a normal ved12 run at.
Just a thought but have they checked the fan? Could it be running all the time and therefore cooling engine down to much. Depending on your fan model if it is the viscous with elec overide it is hard to tell by sound if there on or off alot of the time not like the horton air hubs cannot mistake when fan is running on them.