just picked up my ultra guage.awsome little device.my temp readings are any where from175 to 186 in varied driving.175 on flat highway and 186 around town.ambient temp is around 50 farenheit.could the thermostat stick open or is this normal.truck has new rad and original thermostat.gonna turn of the mpg feature though
thanks
brett

 

T-stat is bad, you should be in the 190-200 range.

 

If you are sure that it is the oem stat it does sound low. There is a 180F stat that guys have been installing, but it keeps temps in the 185-195 range. If someone installed a in-line stat option (there would be a box on the radiator hose) then you could have those readings. Or engine coolant sensor could be bad, one way to check that is cold start in AM. Ambient = IAT = Engine coolant, or pretty close. So engine coolant sensor and Intake air temp should about match, as well as the air temp in the parking area.

 

An easy way to see I'd the stat is stuck open, on the first dire of the day, let it get up to temp for a few minutes, stop and shutoff the truck, and feel the lower rad hose. If cold or much cooler than the top hose, the stat is shut. If already the same temp, likely it is stuck open. Not too often we hear of too low temps on here!

 

thanks,i will do the tests this morning.
brett

 

replaced thermostat with motorad soft spring temp readings are 194-197 on highway and 194 to 201 around town.more where they should be i suspect.
thanks
brett

 

They are right on the money.