Cooling Fan Operation with Engine Off
>The issue is: do the cooling fans of the S4 come on during hot days after the
>engine has been shut down and the key removed? Some said no. But the owner's
>manual of my '90 states that they should, given the right readings from the
>various sensors. It makes mention of the hood safety switch.
>Well, what is it fellow shark-owners? Do your cooling fans ever come on during
>hot days when the engine has stopped and the key removed?
Located on the top of your intake back towards the airbox is a thread-in temp sensor that has 2 wires plugged in to it. This is the intake temp sensor and any time the intake reaches a certain temp the cooling fans will run even with the key off. They shouldn't run for more than 5 minutes or so. If they run for more than 30 minutes that switch could be bad and will need to be placed.
Part # is 928.606.217.00 and Porsches retail is $26.70 , but it can be purchased for less at certain places.
BTW, your combination alarm/fan safety switch under the hood does turn the fans off when they are activated by this temp switch if the hood is opened.
I had it happen once, but the conditions were extreme. Just cruising (~75) up I-5 southbound (from the Devek gathering back to L.A. area), in 108f air temps. At the top of the Grapevine at Tejon summit (-maybe- 4000ft), I pulled into the rest area and parked. The temp gauge had been running a needle higher than the third mark, instead of two needles lower where it normally lives. I guesstimate that the third mark is 190f, and two needles lower is 180 thermostat point. Anyway, the fans ran for less than my five minute "pitstop", and the gauge read back at normal when I restarted.
That is the only time in a year of ownership and hot-weather driving that the fans have stayed on more than a couple seconds after the key is off. It's also the only time the temp gauge has been above normal, including stop-and-go driving in 100+ heat with the AC on.
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