my radiator temp keeps going from 190 to 200 when im driving, i checked my radiator its filled my, coolant tank is topped off so, i bought a new radiator cap. i dont see any leakes on the driveway, so what giveswhy is my temp constanly going from 190-200 and then back down to 190?

 

Mine also dances there when it's below freezing with no cover on the grill. I'm thinking it's just barely warm enough to open the thermostat.

 

its 68 degrees here, its like low 40deg in the mrning and low 70deg at midday, but the temp keeps going up down 190-200 range.

 

My truck did that for a little bit when I changed out my water pump but it's actin normal now... Did you do anything to your cooling system lately? Maybe it has an air pocket in it somewhere

 

mine just started doing that to and i didn't touch the cooling system it was about 55 degrees when it started just last weekend but wasn't doing it at all when it was real cold

 

It never warme dup enough when it ws cold to open the thermostat so they gauge never moves.

A 10 degree swing in the gauage is normal at any time. Remeber these gauges are just dummies responding to what the ECU says to set them at. It ha sits own notions of what the readings should be at any given time. Unless it quits working or consistently goes over 240 its normal.

 

i did nothing to the cooling system, it started getting warm out now my temp gauge has a 10 degree swing, it just not normal to me. this truck is my first diesel and id rather be safe than sorry.

 

Mine is alittle floppy too. I usually get parts from Cummins south. The thermostat I bought last was AAP. It is crap, I wouldnt worry to much. Get another thermostat if it is jumpy

 

floppy gauge

 

It's the thermostat opening and closing, totally normal.