WTF Temperature guage moving Help Please

[LamaRossa]

Yes i've spent an hour reading all the posts

CAr
89 SUpra turbo 216k 100k in a rebuild motor MHG ARP the whole 9 yard

Diagnose
water pump works because the upper rad hose has pressure

fan clutch works fine

Problem

68 deg tonite driving on freeway notice temp usually sits at 4 oclock but tonite its about 2 oclock running a bit hot

my temperature guage has never moved

turn on the heat it went down

pulled ova no overflow or bubbles on the overflow bottle which is a good thing

noticed that one of my wire on the thermostat housing was broken off , the bottom sensor with one wire blue with white strip
The senosor is on bottom of the thermostat hub where the rad hose goes in to not the housing on the block

anyone knows what the hell this bottom sensor does. ????

i respliced it but would this cuase my car to run hot and move the temp guage???????

also notice tonite after driving the car for 35 min the top rad hose still hard meaning i think my thermostat is stuck close

but did not overhead driving home maybe because i drilled holes in the stock thermostat so that it still would flow a lil when it is stuck

anyone got a clue????? comments are always welcome

Ciao

Lamarossa

 

[Eric_Odie]

for me, my gauge started to move and die out when that wire was loose and coming off the blue thing. what i did was put that wire back on the blue thing and taped it with electrical tape so that it doesn't come off again, and after that my gauge worked fine and still works fine...

 

[DrakeMK3]

If it's the sensor with the round blue connector, that is the connector for the electric a/c fans. I don't know how that would affect your temperature needle unless you were running a/c at the time your temperature rose.

 

[SupraMario]

if you thermostat is stuck open you should be over cooling, 99% of all the thermostats now have a fail save where it opens when it fails, I had same well similar problem, my gauge read almost hot then after driving for like 2 days that way, it died. i replaced the theremostat and it works just fine now.

 

[Supra Blues]

I would also inspect my t-stat.

But, get that wire fixed too.

 

[lagged]

eh a friends tstat just failed shut the other day, so dont rule that out.

 

[14u2c]

I was having the same problem on monday, so I flushed the radiator and refilled with new fluid. Than jacked the car up and burped it. No more moving needle. Good luck Rafael.

 

[LamaRossa]

Thank you friends

just got up im heading to toyota for a new thermostat and o ring also planning on flushing my coolant system today
hopefully all is well

thanx again for the responses i got mad work to do

Ciao

Lamarossa

 

[LamaRossa]

Yup new coolant and new Thermostat from toyoa def did the trick


Drove for an hour in the hot no problem

thanx again


Ciao

Lamarossa

 

[DrakeMK3]

Glad to see you fixed your problem. My new thermostat should be here Tuesday so hopefully I'll fix mine, too.