radiator fan problem

[smallbrady89]

so today i started up my 92 lumina 3.1L and let it run to warm up so i could test the heater before winter comes. the heater worked fine so i went to shut the hood and noticed that neither fan had come on. so i waited a few more minuites (about 7 min after i started it) and still neither fan had started. about 2 min later i saw some smoke comeing from around the intake manifold but it could have been comeing from somewhere lower and just came up through there. so i decided that was enough and shut off the car.

how long does it useuly take for the fan to come on and whats the first thing i should be looking for to check for the problem? ive already checked the connectors to the fan motors.

by the way when i tested it it was a partly cloudy day and was about 20 degrees C.

[jeffcoslacker]

From a cold start, the fan(s) usually won't kick in until it's ran maybe ten minutes or more...if you hold the top rad hose, you'll feel the rush of warmth when the thermostat opens, assuming it's working ok. Once you feel that and the hose gets quite warm, pick the idle up to about 1800 rpm and hold for a couple of minutes and the fans will usually kick in pretty soon, cycle and turn off again...

You are probably seeing the result of either a small intake gasket coolant leak, or a small leak from the throttle body preheat bypass, a fuel line sized coolant hose that goes from the intake up into the throttle body...then as the surface of the motor warmed up, the coolant laying from the leak started cooking...use a mirror and a flashlight to have a look under and behind stuff just above the source of the steam, and you'll find it...also could have been oil smoke from a leaking valve cover gasket cooking off an exhaust manifold...real common also...

[smallbrady89]

ya i know the thermastat is working because the coolent was warm when i felt the rad cap (no i dident open it) so tomorrow i will run it again and see if the fans kick in.

[richtazz]

To test engine cooling fan operation, turn the a/c to max. The fans should kick on.

[Blue Bowtie]

Right. You may have been taking enough heat away from the engine with the heater and blower, and kept the coolant just below the fan turn-on threshold.

[Kupop]

My fans *do not* turn on... my temp gauge will climb above normal operating range and even if I set the knob to MAX AC they will still not come on.

Is there a temp sensor that triggers the fan? If so, how can I test it, where can I get one and where is it located?

If not, what else would be the problem? relay? fuse? location of such part?

Thanks in advance... If only I knew as much about this Lumina as my MR2

[richtazz]

there are two relays in the underhood relay center (front passenger side) that run the two engine cooling fans. They are the same relay number and can be switched to see if one or the other is bad. The CTS (coolant temp sensor) for the computer also signals the fans to kick on, so if no CEL (check engine light) is on, the sensor is probably good. The factory turn on temperature for fan #1 is about 230 deg f, (112 deg c), so it can get hot before the fans will kick on. The heater control unit should energize the aux fan relay when the switch is set to max, automatically turning on the #2 fan independent of engine temp. I would start by checking the fan relays.

[Kupop]

Can the relay be found at most any auto store or is it dealer only?

[richtazz]

They are very common relays, and should be available at most any auto parts store.