S10/Blazer Coolant temp sensor

[GreenBook 10+ year member]

Someone on here should know this. I need to know where the coolant temp sensor is on a 4.3 motor; swapping one out tomarrow cause it threw a code. It's a '94 s10 if it matters somehow.

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[Stephen_c 10+ year member]

on my 95 c1500 4.3 it has 2... 1 for the gauge and 1 for the sensor. The one for the gauge is on the drivers side head near the exhaust. The one for the engine comp is ontop of the intake manifold

 

[bones22 5,000+ posts]

top hose on radiator

follow it to the intake manifold

thats where its at

 

[GreenBook 10+ year member]

Well it's running pretty rough; but the gauge doesn't work either. I better just do both since I'm draining the coolant anyways. The code that came up didn't specify. Thanks for the crazy fast reply.

 

[pre98zetec 10+ year member]

depends on if you have a TBI 4.3 or a CMFI 4.3

TBI:

CMFI:

 

[GreenBook 10+ year member]

'94; so tbi. that pic helps alot thanks. now i know what it looks like.

 

[pre98zetec 10+ year member]

they also made CPFI in 94. but only some. most were TBI until 96.

 

[GreenBook 10+ year member]

it's tbi; ive torn off the upper round intake before & saw the injectors. It's not my trunk im working on though.

 

[pre98zetec 10+ year member]

im not saying its not, just stating not all 94's were TBI.

 

[SICCMAD3 10+ year member]

What code did you have

 

[GreenBook 10+ year member]

What code did you have

I dont remember what code came up; but the book that comes wih my obdI scanner for gm's said coolant temp sensor. Like I said, his gauge doesn't work at all, so I'm just going to replace both sensors so I know their good.

Problem is my friend knows nothing about cars(maybe less then nothing), and thinks fixing this one little sensor will be a miracle cure. I told the guy I think he has rust in either his fuel pump or tbi injectors; cause the truck sat for a few years before he got it. Less intelligent people always seem to be the ones even less likely to listen to people's advice & shared knowledge.

 

[SICCMAD3 10+ year member]

are you sure that there are 2 sensors? i don't see alot of old s10's like that is the reason i ask, because most everything i see has one sensor and the information is shared between different modules. if the car sat for that long, does it even run, and if so i would test the 5-volt reference and signal circuits at that sensor.

 

[GreenBook 10+ year member]

There is a sensor on the drivers side head, it doesn't look much like a temp sensor though, the truck runs, but barely. stalls out when you hit the gas or put it into drive. kicks out black smoke too.

 

[GreenBook 10+ year member]

Well, yesterday I replaced the sensor on top of the intake. The gauge still doesn't work; but it runs infinitely better. No stalling sputtering or misfires at all. It does still kick out black smoke though when you gas it; so it still might have bad gas or a choked up exhaust. Thank you for those pictures, they helped alot.

 

[Blazin_Jason 10+ year member]

As mentioned the sensor for the gauge is in the head. You can easily test the gauge to make sure it's the sensor that needs to be replaced. Take the sensor wire and ground it somewhere on the truck. Turn the truck "on" not started and the gauge should peg all the way one way (up/hot).