Cooling Fans
 

Guys, have a question: I got a 98 Z28 and for the longest time now, every time when starting up the car, the fans will kick on from either a cold start or warm start. They stay on for a bit, shut off, then come back on a minute or two later for a quick second, then shut off. They seem to operate correctly during driving, but coming on at startup has me confused. Any ideas on what to check or replace to fix this? I was reading about a temperature sensor and maybe a fan relay and was wondering if there is a way to check them or just replace. TIA.

Is the A/C or defrost on?

No,nothing is on.

Is the temp gauge working ?

i have the manual fan switch on mine with led's, and the led's light whenever the fans are on. I know the fans will always come on low speed if the ac compressor is running and you are less than 30 mph, along with being over 226° F coolant temperature. and high speed fans only if over 234° F or if the AC pressure goes over a certain amount. but i've noticed over the years when i've started the car cold or warm with none of those conditions present the fans will be on low speed for a brief amount of time then go off. i think this is a self test of the cooling fans by the pcm, it mentions something like that in my service manual. it only happens once in a great while, and it's always been low speed. i've never had the fans come on high speed after starting unless the AC was on and it was hot outside, or if the engine heat soaked after shutdown on a very hot day.

That is what I was thinking for as far as I can tell, everything is operating correctly and it never overheats. It must be just a self-test the fans go through at start-up but it's worth keeping an eye on.

The gauge does work and reads correctly.

Look for a flakey ECT sensor connector. Especially if
other things like intermittent stumbling / choking idle
are going on with / opposite to the fan situation.