I've replaced just about the whole cooling system in my car, and it still wants to kick 1 out of 2 fans on at 240 degrees. What gives? I've checked the stat, new, works, apparently it's for the stock temp of 190 as per autozone. Anyone who's able to keep their temp at around 180, 190.. help please!



----Read Willie's Article. Gonna follow exactly what he describes to cool the car down. Retarded me.

 

What kind of car do you have? What exactly did you replace? You gotta be specific!
To reply to your post, did you replace the coolant temperature sender/switch? It may be faulty or have a loose connections. May be a bad ECM (doubt it though, u'd have many other problems!)

 

Sorry there, man.

1989 IROC V8 5.7 TPI

I've done this so far:

Radiator - new
coolant temp sender - new
coolant temp switch - new
oxygen sensor - new


Now that you mention it... I've been getting code 33: bad ECM or MAF.

Could this be the culprit?

 

Funny enough i've been running that code too, so i'm curious what your outcome will be. I'm gonna replace the ECm and see what that does. Your ECM does control the fan switch via input from the coolant temperature sensor, so provided it's the right one, installed correctly, with a sold connection, your ecm could very well be it. I just wonder if a cpu can only sorta fail like that.

 

It's highly possible, overheating ---> CTS sends info to the ECM... ECM part of the cooling system.. it's VERY possible. If you replace your ECM before I do, keep me up to date if it helps oyu a bit on heat-wise, I would definately appreciate it.

 

DON'T replace the ECM yet, replace the primary cooling fan relay first. 89 had the oval shaped relays which had many reliability problems. I'll bet the ECM is OK. Ditto for the SES code, intermittent MAF power and/or burnoff relay-replace both MAF relays. The fan relays, MAF power and burnoff are all the same part number. NAPA # AR-279, 14089936 GMSPO #. In fact, replace all 4 'cuz the aux one will bite the bullet when you least expect it. Dan, 89 IROC who has been there!

 

just replace the fan switch also... stock switches dont turn the fans on till around 230 ish... any performance shop will have switches thatr turn fans/s on at 210 or whatever you want