'93 lumina overheating

I don't think my radiator fans work b/c I was stuck in traffic yesterday and my car began to overheat, and i could smell radiator fluid burning. I noticed my fans never came on. I could hear the radiator fluid was boiling. What might be the problem with the fans? how do i check the relay? I know the motors are okay, I jumper'd them to the battery. Plan of action? :confused: Thanks

Your coolant temperature sensor may be heading south. What engine do you have?

3.1 liter. I recently performed a total back flush on the cooling system and refilled 50/50 water-coolant. Also, my car doesn't overhead while moving, only when stuck in traffic or idle. Another concern is that my Idiot light doesn't come on, now that sounds like a sensor to me. Just don't know where that is. I'll look it up in my Chilton's book this afternoon. From what I've read, there are 2 sensors, idiot light and water senor. Do they both control the fan?

Right, there are two sensors. Nope, the one for the dash light is only for the dash light, and only has one wire. the one that tells your ecm how hot your car is has two wires (or three)?


I just thought of something... you mentioned you just performed a flush n fill. Did you bleed the air from your coolant system?


Also, enter diagnostic mode (paper clip trick) and if your fans turn on (at least one), you'll know for sure its not your relays or the wiring from the ecm.

See if they turn on when the A/C is on. That should start them regardless of sensor input. If they don't, or just the aux fan comes on, try a new relay. Relays are easy and cheap, and common to fail. If the aux cooling fan runs with the a/c on, but the primary doesn't, you can swap the relays and get your primary working until you get a new relay. Just don't use the a/c if you run it like that.

The primary will only run when temp is about 2/3 up normal temp range, but shouldn't allow it to start boiling at idle.

I just thought of something... you mentioned you just performed a flush n fill. Did you bleed the air from your coolant system?

Good point. That'll fool the sensor sometimes, too. Can't sense air pocket temp.

Where can i find the coolant temp sensor on the 3.1 liter engine?

Driver side fan came on when A/C was turned on, switched relays, same fan came on with A/C. Checked OBD codes and showed nothing BUT both fans ran during diagnostic. I'm guessing now it's the coolant temp sensor but the book does a poor job of telling me where that is. (adjacent to EGR pipe, but where is that?) Thanks

COOLANT TEMPERATURE SENSOR


On your 1993 CHEVROLET LUMINA-SEDAN/COUPE, the COOLANT TEMPERATURE SENSOR is:




UNDER HOOD, DRIVER SIDE, REAR ENGINE AREA, MOUNTED ON REAR OF INTAKE MANIFOLD

COOLANT TEMPERATURE SENSOR


On your 1993 CHEVROLET LUMINA-SEDAN/COUPE, the COOLANT TEMPERATURE SENSOR is:




UNDER HOOD, DRIVER SIDE, REAR ENGINE AREA, MOUNTED ON REAR OF INTAKE MANIFOLD


Damn, what a bitch to get to.

Okay, so I found the temperature sending unit (1 wire) driver side rear engine. But where is the temperature SENSOR located (2 wires). The book doesn't say. I believe it's the SENSOR that controls when the fan comes one at 195 degrees farenheit. I already baught the sensor but can someone help me locate it? Thank you.

I'm also looking for the temp sensor my temperature gets up to the half way mark and the cooling fan does'nt come on, I think half way is 210 degrees I'm not gonna let it get any hotter since I just got through doing a head gasket job which was no fun. I checked my 2 fan relays with a fused wire from the battery positive and ground they clicked and continuity was good, the coil and contact terminal numbers are on the relay,might save buying a new relay. also unplugged fans and applied battery power fans were good.
The guy at the auto parts store told me there are two temp. sensors ,one by the thermostat, which is easily found ,three wire, and the one he sold me a two wire, the one by the thermostat is for the gage? Ithink and still looking for the other. Oh by the way both fans run when the ac is on drivers side stays on and the other runs intermitently. The repair manual gives testing info for the sensor by the thermostat, but does not mention another, if I find it I'll let you know. 96 lumina