Overcooling issues

[GI-John]

Of course it has to happen to me, but that's just my luck.

My jeep normally runs cool (150-170) but for the last 2 days the jeep overcools (the gauge barely reads)

6 month old thermostat (with bleeder valve)
6 month old temp sensor
6 month old heater control valve
original fan/clutch
new serp belt (if that matters)
old coolant(3 yrs) that is being flushed/changed as we speak

No heat in the cabin, and the mechanical fan constantly runs. I did the search, and checked the fan clutch, and it seems like there is very little resistance either cold or lukewarm.

Any suggestions on what the hell is going on?

Any and all help is appreciated.

John

[GI-John]

update:

No fault codes
completely covered radiator with cardboard... temp rises slightly
a little warmer in cabin but by no means hot.
I checked the upper rad hose, and it gets hot. It also gets hard/soft before after the thermostat opens

:dunno:

[Clean Racing]

the thermostat is most likely stuck open so the jeep never has a chance to warm up. Replace the thermostat, and cut the little wiggle valve out of it for a steam vent.

[Kejtar]

the thermostat is most likely stuck open so the jeep never has a chance to warm up. Replace the thermostat, and cut the little wiggle valve out of it for a steam vent.

wiggle valve? you mean the BB? :D

[Rev Den]

Check if all 4 tires are.......nevermind :D

if the gauge is not reading then I would suspect a stuck open thermostat....at least partially, seems a good place to start.

Rev

[Heavy_Equipment]

I just had the same problem, and a thermostat swap fixed it right up.

I put in a stat without the jiggle valve and it works fine.

[GI-John]

Well, it seems like it was a combination of the fan clutch and the T-stat.

I really wanted to think it wasn't the t-stat, but the K.I.S.S answer was too simple...plus it was new. I bought one of the "good" ones that lock open when they fail... It locked open, but after I unlocked it, it worked fine. I replaced it anyway.

I'll check my tires for ya Rev.

[Spanky414]

I've tested my Tstats in a pot of boiling water to make sure it works fine. Seems like a good idea to me anyways, plus I wanted to see one in action. :)

[Spanky414]

Forgot to mention that I used a thermometer to make sure it was opening at the right temp.