I have a 96 z28 LT-1. It overheats at idle after driving for a while. While driving, temp is good. Im not hearing any fans come on as I believe there are up to three cooling fans and fuses. Coolant levels are good. Any ideas as to my problem?

 

my car will get hot at idle too how high does your gauge go

 

lol. Let the car idle till it overheats, then open the hood and look at the fans to see if they are spinning. If you look very carefully you will notice that the car uses 2 fans and 3 fan control relays. Also if you look inside the fuse box, you will see the 3 fan relays, and fuse #6 which provides power to the relay windings. You will notice that all components are labeled for your edification. Power for the fans motors comes from a fusible link and then through the make contacts of the fan relays. Depending on which relay combination the PCM activates, the fans can be off, or on at low speed, or on at high speed.

 

had the same problem with my 95 z28.i replaced all the relays.found a wiring diagram for the fan systems.checked continuity from the pcm to the relays to the fans as well as all the coolant sensors.also mesured resistance at the sensors.i found absoluty nothing.my gage still read almost in the red at idle especially in traffic.i was stumped.then i read a paragraph in alldata that said the cooling fans on afactory carare designed to com on low speed at 223 degrees.so i hook a scanner to get a true temp. reading.sure enuff it came on at 223.but my dash gage was almost in the red.i spent a whole weekend chasing a problem that wasnt there.the gage was giving me an anxiety attack so i installed a 160 thermostat and had my pcm tuned so the fan comes on sooner.no more anxiety. bottom line is these cars were built to run a little warmer than most

 

turn the a/c on and the fans should come on. if not there is something amiss.