92 s10 temp sensor issue

[jumpingjohn]

had a 92 s10 for about 1 1/2 years. ever since i have had it, the remp has read nothing never moves. i have regularly checked the coolant leel.

recently i topped it off, and now the gauge says i am overheating, maxed out. and it tells me to check gauges. i know it isnt overheating, it is just messed up.

i was just boggled why it would all of a sudden change after 1.5 years.

Does anybody have a ny suggestions? how to fix this problem?

[s-dime blaze]

new thermostat maybe

[jumpingjohn]

already put new thermostat in

[DeathSlinger00]

the beginning of your post was making me think you should replace the sensor. but with it now maxing out, i'm thinking some kinda wiring/gounding issue.

[beaniebmx]

more than likely the rear sensor for the gauge is bad.

mine did the same, when i first bought it, it would stay at the very bottom, then it pegged to the top at start up, and then it started to fluctuate.. it would go from flat bottom, to pegged at the top so fast it would make a ticking sound, and it would tick 1-2 times a second randomly, kinda like dragging a stick down a metal picket fence randomly.

the weird part is, i have an aftermarket water temperature gauge thats screwed into the thermostat housing where the stock one was, but the gauge still jumped around and acted weird.

which leads me to beleive its the rear gauge sensor.

[Blktalon456]

I have a 93 2.8l and it stays at the bottom and never moves. Which sensor is for the gauge and which one is for the computer? I know of two. One on the t-stat housing(2 wire) and the other on the front of the driver side head(1 wire). I could use some insight on this as I want my gauge to work.

[beaniebmx]

the one on the back of the block near firewall is for the gauge.

[jumpingjohn]

well about a year ago, i replaced the sensor on the thermostat housing. but it didnt change anything at all.

so does anybody have any pics of the other sensor or can give me instructions on where it is. and what it looks like
thanks

[beaniebmx]

its on the very back of the head, basically touching the firewall by the fuel filter.

its on the drivers side, right by the valve cover, has a 1 wire plug going into it

but mines a 2.5l 4cyl so it might be in a diffrent area then the 4.3

[Blktalon456]

Alright for all the 2.8 tb people the temp gauge sensor is on the FRONT of the driver side head. A single green wire is ran to it. I just grounded the wire against the cab while running and the gauge went straight to 260. Let go and it dropped back to the bottom. Now I just need to find the sender at the parts house and I and everyone else that has this problem can fix the issue. Good luck people.

[basist_4]

On the 4.3...The one wire sensor for the temp gauge is on the passenger side...The 2 wire sensor by the thermostat is for the ecu...

easy way to check the 1 wire sensor (regardless if it's a 4 or 6 cyl) is to take the plug off the sensor and use a paper clip to ground it to the block...with someone sitting in the cab...turn the ignition on (you don't need to start the engine) and when you touch the paper clip to the block, the gauge should peg...when it's ungrounded, it should read zero...

with the issue you have, where the gauge is going from 0 to max...it sounds like you might have a issue w/ the wire...check/trace it to see if it's grounding out against something.

FWIW...my temp gauge didn't work when I bought the truck...I had to replace the sensor that went into the block (the 1-wire sensor) AND change the thermostat to get my temp gauge to work.

Hope this helps

[jumpingjohn]

thank you for the input.

i will try this out.
thanks blktalon456
your help is appreciated b/c its a 2.8
and thanks basist4 on how to test if this is it