Engine Compartment Cooling Fan

[dinicor]

Is there an easy way to test the engine cooling fan in these cars? I can see the engine compartment temperature sensor - it is properly in place and wires in place. I tried unplugging it to see if the fan would turn on - it did not. I read somewhere that it would turn on immediately once unplugged?

Assuming this is true, then is the fan cooked? How can I test it and would it be something else if the fan doesn't come on. Thanks!

[JFP in PA]

Is there an easy way to test the engine cooling fan in these cars? I can see the engine compartment temperature sensor - it is properly in place and wires in place. I tried unplugging it to see if the fan would turn on - it did not. I read somewhere that it would turn on immediately once unplugged?

Assuming this is true, then is the fan cooked? How can I test it and would it be something else if the fan doesn't come on. Thanks!

 

The easiest way is to test it with a Porsche specific diagnostic tool like the Durametric system, you can simply activate it.  I would be surprised if the car did not throw a code if the fan was bad.

[Ahsai]

You can unplug the fan at the spoiler then supply 12v to it with the correct polarity (brown=negative). The fan consumes a few amps.

To test the sensor and DME activation of the fan, you can probably use a hairdryer to blow hot air onto the sensor once you stopped the engine. Since this is an NTC type sensor, I would expect the fan to come on if you bridge the two pins of the connector. I've never tried that though. There's also a relay between the DME and the fan that can be tested too.

If you have Durametric, it can activivate the fan on demand.

Edited September 28, 2014 by Ahsai

[Loren]

I doubt there is anything wrong with your engine compartment purge fan.

The engine compartment purge fan rarely comes on. Mine has only come on twice -- and I live in 90 plus degree California! Here are the conditions the fan comes on at. 

From the service manual...
"Switch-on conditions for engine compartment fan (this fan pulls air into the engine compartment) The engine compartment fan is switched on when the engine compartment temperature is > 176 degrees F or the coolant temperature is > 216 degrees F. 
After-running of engine compartment fan 
If the ignition is switched off and the engine compartment temperature is more than 140 degrees F, the DME control module remains in readiness for another 20 minutes. During this time, the engine compartment temperature is retrieved every 10 seconds. If the engine compartment temperature is > 185 degrees F , the engine compartment fan is switched on for 20 seconds. If the engine compartment temperature is still > 185 degrees F after this time, the fan remains on for a further 30 seconds."

[dinicor]

I did try bridging the two pins of the connector at the sensor and nothing happened.

I have never heard the fan go on or seen it running.

I get the needle past the centre mark on the dash gauge, which is why I'm looking into it. I have no leaks, the front fans seem to come on and I cleaned the rads. No coolant leak as far as I can tell and the reservoir is spot on.

Thing is, car runs great... needle stays at top dead centre most of the time, but as soon an I get in a bit of stop and go traffic, the needle creeps over centre just a bit and then stays there - doesn't get hotter, but never really ever gets back to top dead centre, even when I get out of traffic.

Anyway, stupid question but, easiest way to get 12v to the fan? Any suggestions?

Thanks!

[Ahsai]

First I don't think you have any problems in your cooling system. Also keep in mind the temp gauge in the cluster may not be completely accurate. You can use a generic obdii scanner to verify the coolant temp.

I second what Lauren said but of course it's also possible your engine fan is not working.

You can get 12v from any portable battery jumper, a battery charger, or the positive jump point in the engine compartment, which is directly connected to the battery and not fused so be extremely careful if you tap power from there.

[Silver_TT]

Save yourself time and test it with Durametric by activating it.  You won't hear it too often but I would hear it a lot in my Turbo when I got out of the car on hot summer days...it would run for a few minutes after my car was parked in the garage to cool down the engine.  I concur that they don't break often, but they do break.  I had to replace a bad one in my Turbo (pulling too much amps and blowing the fuse) and I believe what I replaced was not the original fan (because it had a manufacturer date that was many years after my MY) so it might have even been done twice.  I used my own battery to test the fan independently, just need some long cord since the battery is in front.  Also FYI, if memory serves, you don't need to worry about pos/neg for the purge fan, as it will operate in either direction.

[creekman]

In the event you need a engine room blower fan I have a good one...  I'll make the price right since it's just taking up room on the shelf...

[Hilux2400]

This how I tested mine:

 

As you know the sensor is on the right side of the engine on a rubber mount wedged between intakes.  Remove it and keep the wires connected.  Suspend it next to an oven thermometer and heat them both with a hair drier. When the sensor reaches the required temp the fan should switch on.  When you do this place something behind the sensor and thermometer to prevent the overspill warm air heating anything else. 

 

H