Radiator fan not running once the car is hot...

[MrClean]

Fine on the freeway, but once I hit traffic or a stop light, she starts to heat up. Shut her down for an hour or so, and upon re-start (engine not at operating temp, but not cold either, temp gauge at 3/8, the radiator fan runs fine. It seems to be shutting down at some point. Any ideas? Anyone else had this problem?

 

[MrClean]

BTW, after this happened the first time, I turned the cut-in temps for the high and low speed fans to 180º and 170º respectively.

 

[SteveP]

Check your thermostate and sensor next to it. It may not be reading correctly and not telling the fan to turn on.

 

[ChevyKiller]

Good advice - sounds like the T-stat. if you do end up replacing it - try a 170º T-stat...

 

[tmcolegr]

http://s197forum.com/forum/showthread.php?t=7016&highlight=cooling+fan

 

[SteveP]

and a easy check, make sure their is enough coolant in the car.

 

[MrClean]

Check your thermostate and sensor next to it. It may not be reading correctly and not telling the fan to turn on.

Thanks.

Good advice - sounds like the T-stat. if you do end up replacing it - try a 170º T-stat...

Went with the Hypertech 160º T-stat.

and a easy check, make sure their is enough coolant in the car.

+1 Yep. Drained 8 qts and replaced with distilled water, will do again and add back some glycol and Water Wetter.

Took it to the stealership and they replaced the whole fan assembly and the relays. Should get it back this PM if everything checks out.

 

[MrClean]

Got it back and they replaced the fan assembly and relays. Apparently the fan was pulling too many amps and shorting out the relays. Everything appears to be ok....got caught in some hellacious traffic at 3 pm yesterday driving back from the stealership, and running the AC full blast at a dead stop everything worked well.

Any suggestions as to what I should set the cut-in temps for the high and low speed fans? The stock t-stat was a 195º unit, so my guess the engine's normal operating temp is around 196º. Should I perhaps set the temps at 196 for the low speed, and 200 for the high temp? Or (now that I have nitrous) should I set them as low as they'l go (180º high and 170º low)? Wouldn't that mean the fans would be running basically all the time?