so i installed a new coolant temp sending unit today,, i did not drive the car i just let her idle,, she heated up quick quicker then usual, she used to idle at first hash mark maybe a quater. now she holds above 220 with the fans on,, i had a problem with the old sending unit pig tail, the plastic was melted and crumbled off. so now i only have a metal clip on the terminal on the sending unit could she be getting a false reading due to the ambient temperature around the pigtail? she does sit right under the headers should i try insulating that pigtail wire??. or was my old sensor just screwed up for 5 years. i added headers this past weekend.

 

dosent even run for 5 mins and shes up to the red overheating mark!!!! i never had any problems i put headers on this car and i have 15 new problems

 

then you turn her off and let her sit for 5 mins and shes back down to 185 apon start up, then u can actually see the temp guage slowly rising,, either im sensing the ambient temperature around the headers or i must have a bad sensing unit right from the store

 

Could you possibly have air in the lines or incorrect mixture of coolant.

 

im not saying this like you dont know anything but have you checked your coolant level? Is the water pump actually moving coolant? Is the thermostat working good?


As far as the wire you should replace that, the CTS is a thermo-resistor, sending a specific value to the ECM, buy changing the Wire size/material you are also changing the resistance (maybe only slightly, but still changed)

 

the coolant is full,, theres no way possible its gettting that hot,, the upper radiator hose is still ice cold and the overflow bottle has not even expanded the coolant yet soooo wierd,, im stumped

 

which sensor exactly did yo u replace? drivers side, or passenger side?

 

driver side,, i think i may have got black silicone disrupting the threads to ground,, but wouldnt that still be a dead guage and just not heat up to fast,,, the passanger side one is no longer in use i have manual fans now

 

I use plumbers tape when I install mine, so I dont think the silicone on the threads is an issue. I think It may be your messed up wire though. I would repair that then see how it works, it could also just be a part.

 

Yes,that wire needs the "insulation" on it to keep from getting heat from the headers/manifolds.

Also,with the engine cold take the rad. cap off and then start the car and let it run to make sure ALL THE AIR gets out of the system. It can be a PITA on those cars.

Let if get all the way to operating temp before you put the cap back on.

 

OK HERES THE DEAL, i went out and bought a mechanical gauge and my water temp is fine im running the way i always haveyay,, now im going to stick that neat little gauge in my hood scoop on the other side where the fan sensors sit because my fans are manual,, now i still need to figure out that stock gauge myth,, because now i want to run 2 guages ,, where the hell am i gonna find a stock pig tail anybody know of any companys that deal with that stuff????

 

Painless? or classic industries.

 

If you go to a junkyard, they can cut the pigtail socket from a GM vehicle, why spend the money on new when you can get a recycled part??

 

im not even worried about cause i got a manual gauge here,, and besides there no junk yards around here that have any 80-90 gm vehicles i kid you not its all 2000 and upwards here ive been down this road many times