truks temp gauge stays at cold.

[KC2KALI]

Hey everyone..so im new here, just picked me up an 89 mighty max 2.6l auto 2wd. truk is in good condition.im doin a tune up since i got it.but sinse the weather has changed my temp gauge stays around cold..even when i let it warm for a bit, then drive,n drive, but it stays at cold. now if i let it idle after driving for bout 5 mins the gauge will gradually move to bout 40%. jump in start driving.....then right bak to cold. any and all help...much appreciated

[geezer101]

Hi KC2KALI, welcome to the mightyram. Sounds like you might be in need of a new thermostat (symptoms are pointing towards it being stuck open). It's funny how an engine can sometimes run cold even when driving it just because the outside temp is low. I had a car that I'd done an engine swap on it that ran cold enough in peak winter for it to almost stall out (I would have to pull over and let it idle for a few minutes so the thing could get back up to operating temp! I ended up jamming an offcut of corrflute in front of it to block some airflow into the radiator)

[ragragtimetime]

the 1983 had the same issue...choke was on way too long...after driving for over an our still cold in cab. previous owner installed thermostat upside down!

[KC2KALI]

much thanks guys. replaced thermo,gasket,and housing..en everything is good now..works like new​.

[KC2KALI]

upside down?????dont even wanna kno lmao