S14 temp gauge acting erratic after radiator change

[carnal_c30]

hey, I need some suggestions here

the temp gauge on my S14 moved up and down, not quickly but gradually during driving, like it will take 15 minutes for it to warm up to the middle, but then it willmove back down to a quarter between Hot and Cold, then move back up... SoCal isnt that cold!!

this all began after I had to change the radiator, the radiator blew, the temp gauge stayed at operating temp, but I smelt the coolant so I stopped, found out my radiator was about bone dry. I changed the radiator, filled it up, bled the air out twice so far, and the temp gauge is still acting erratic.

also, there isnt any evidence I damaged the motor or headgasket, car runs fine, no oil in coolant, and the oil looks fresh soo... yup not sure whats wrong

any suggestions? thanks in advance

[s13sr20chris]

what process did you use to bleed the air out of the cooling sys? that really sounds like air in the cooling sys. could be a thermostat problem. i have seen that before with the same symptom.

[carnal_c30]

I used the bleed screw on top of where the hose comes out from the motor, I bled it until water came out and no bubbles

the thermostat itself is relatively new, like about 3 months new,

not really sure why it jumps up and down, it sound like air in the system to me too haha but I keep bleeding it and it hasnt gone away

thanks for your help

[180fan]

squeeze on your radiator hoses. After the bleeder bolt, I usually keep filling the radiator, cap it, squeeze the upper radiator hose and then turn on the car for a minute while i'm out front squeezing the radiator hose. Then turn off the car, let it cool down, and fill the radiator more. I get the radiator hoses pretty hard at that point lol yes, a firm grip and the squeeze makes em hard after a while. lol

[carnal_c30]

arity, I'll keep trying to bleed the car, on a steep driveway witht he cap open and all that,

if its not that, what sensor would cause the temp needle to act so eratically?

[s13sr20chris]

could be a bad connection but the sensor should not cause that. its the little one wire sensor next to the coolant temp sensor for the ecm.