So my temp gauge was running into the red zone alot so i changed my temp sensor and now the needle doesnt even move ???

 

Ok so turns out the engine coolent sensor on the drivers side of the engine wasnt hooked up it came lose some how so that solved the gage not working, but my fan still doesnt come on and my gauge shows the red zone at 125, the fan works cause when the ac is running the fan works. Can anyone tell me when the fan is suppose to turn on ????

 

https://www.thirdgen.org/forums/cool...ans-arent.html

 

Do you have dual fans or one single fan?

 

i have a single fan !!

 

Okthe fan circuit works, because it comes on with the AC as you mentioned.

There is a switch that looks like the temp switch, but it's on the passenger side above the dip-stick/below the exhaust...between the 4 and 6 cylinders. This is the "fan temp switch" that controls what temp the fan comes on. Make sure it is there/hooked up. Ifi t's bad/not hooked up, the fan never gets the message to turn on. This is a common item that is missing/broken. the single wire from this goes up to a relay that switches the fan on/off. So, lets do some trouble shooting.

1. If the switch on passenger side is hooked up (if not, hook it up). Pull the wire on it (Should be a clip on connector) and ground it. WIth the car in "run" the fan should turn on with the connector grounded (any chassis ground should work).

2. If the fan turns on this way, hook it back up and run the car to operating temp. If the fan doesn't come on, the switch may be bad. I'd replace the switch at this point just to be sure. They are like $20 from autozone. However, there are a few other things we can check first.


2. I don't have a Camaro, but if the switch on the passenger side of the block is hooked up, the wire leads to a fan relay. It's possible this relay is bad. I don't know if they are in different places, but my relay in my 84 T/A is up on the firewall near the brake booster. Should have 4 wires coming out of it. Should face the "front" of the car, to the outside of the brake booster. It costs maybe $15 for a new one from autozone. You can test it by pulling the relay connector and shorting the two fat leads on it together with the ignition in run. This bypasses the relay. IF this makes the fan run, then the relay is bad. IF this does not work, then you have other issues.

Let me know what you find out after doing this.

 

I have been having this trouble for years with my 88 IROC 5.0 TBI. Over the years I have done everything told to me by Chevrolet and my mechanics and nothing has made this problem stop for me. My temp gauge in the car runs nicely at 210 220 while driving. In any stop situation it runs all the way up to the top of the redline 260! The fan (single) comes on and the temp heads back down to 230 240. If the car is sitting idling in the garage, I have the same performance. Here is where it's at with repairs - New ECM - New A/C Compressor, just went bad and replaced it - New water pump, the old one was fine - New T-Stat 190 degree - New temp sensor, the one in the in the manifold - New Radiator - and everything that goes along with all these things such as hoses, clamps and the like. The temp gauge still reads this way no matter what I do. Reading this post, the only thing I can tell that might be left is the temp switch between the cylinders, which I didn't know about until I read this or maybe there is something wrong in the new ECM. I am taking this info to the shop with me to see if they can determine if the temp switch is bad. I don't know if this will be the issue, and I think I have replaced every thing else at this point. I really don't want to start adding manual fan controls and the like, I just want the car working like it was designed to. If I am understanding what I am reading here, it sounds like the temp switch and the ECM are the likely issues in my car. Can anyone else weigh in and let me know what they think? Since I am having no luck having all these repairs done, I would like to just tell these guys what it is and get it right again. Thanks for reading!!

 

Just got the car back from having the Temp Switch replaced. No change. The car is running up into the red line before the fan will kick on. That takes it back down to about 240. Steady driving seems to be the same performance. I am now going to take a look at having this computer re-programmed. I'm told it's about $140. I am also going to see what another new one might cost me. I am at a total loss on what else to do. We feel like we have replaced everything it can be. Except the ECM - again, as that was replaced some years back with a new one. If anybody sees this post and knows what I am missing, please tell me. Thanks for reading!!

 

Might seem silly, but do you have an air dam?

 

The front clip / bumper is the air dam right? Then, yes I surely do ;-)

 

No the air dam hooks to the bottom and directs air onto the radiator.

 

Hate to say it, but I guess I would have to look and see ;-) Never really thought about it. I think you must be getting at the air flow over the radiator, but that gauge shouldn't be hitting that high when not moving. I think the only way to be sure is to find out what the engine is actually running at by some other means. Not what that gauge in the instrument panel says. I just don't know how to get it done. This is why I am thinking I should just have that ECM flashed.

 

Air dam hangs below the lower radiator mount.
Search--
Air dam
In the--
Cooling
Forum.
I would post links but IDK how from my phone.

 

I will, but I am trying to get advice on that ECM. Even if that dam wasn't there, this car should not be doing this. It should be able to sit and idle without hitting the redline. We sit in traffic here for a long time! Nothing going to be moving over the air dam like that.

 

Gotcha!!
Before I found TGO I had no idea there was such a thing.
Best of luck!!

 

If you have a 195°f tstat and you're running +15-25° hotter on a nice stretch 'by the gauge'... the gauge is more than likely off.

ANY, excluding tta, stock fan switch for an f-body is 238°f.
If your gauge is already off by at minimum 15°, that would make the gauge read 253° by the time the fan turns on.

The cooling system is seemingly not at fault, you're putting to much faith in the OE gauge accuracy 21+ years later.

airtex/wells sw505 (autozone p/n) is a 215° fan switch. it's a more reasonable fan temperature for (stock) TBI cars.

 

I understand - I may very well have to do something like that. I have even replaced the circuit board controlling those gauges. I really mean I have done anything & everything to try and get this corrected. Do you say then the computer reflash won't help?

 

Yes, these gauges are highly inaccurate.

 

A single fan should begin to spin at about 235 degrees.

Most 50/50 mixxed coolant will boil over into the overflow tank @ 260 degrees. If your gauge is "pegged" and the overflowe bottle isn't boiling over and spewing hot steam everywhere - your gauge is wrong.

 

If we are talking stock gauges in a 3rdgen, the ECM has zero to do with the gauges. The plastic circuit board on the back of the cluster doesn't really affect the physical workings of the gauge either.

I wouldn't say the OE gauges are horribly off in general but, there are cases once in awhile, one is. There are many factors that affect that as well though.

It would probably be best to confirm engine temps by other means than just the gauge. IR temp gun, cooking thermo in radiator with cap off, scantool, aftermarket gauge.

 

So I pulled the temp gauge out to see if anything obviously wrong. Didn't see anything. Put it back in and now it is either pegged all the over top or bottom. Took it out again to put a multimeter on the socket and test resistance. Took some pics - I think everything up to the gauge is ok. What do you guys think? I am thinking of just trying to find another gauge and see what happens. Pic shows where the meter was plugged in. Ohms rises the longer car runs. As it gets hotter.

 

If the gauge just spikes, it is grounding out somewhere. If it doesn't move, it is dissconnected.