aldous

hi everyone

my engine cooling fan is constantly on.. even after the car has been idle for days, when i start it up, there it is... is this normal? i live in a hot country (australia) but seems excessive.. it's quite noisy..

thanks for your advice

a

bet

When you say cooling fan...are you referring to the radiator fans up front or the fan for the engine compartment? If the radiator fans up front...be aware they run no matter what the engine temp. if the AC compressor is on, so if your AC is on those fans will run. Make sure the AC is off when starting the car after it has been idle of a day and see if those fans are still on.

The engine compartment fan is triggered by temperature only. If it comes on immediately when starting the car after it has been off for days, then you likely have a problem. I have read of relay and/or sensor failures. Usually easily fixed under warranty.

aldous

yes.. i meant the engine compartment fan.. and i suspect the sensor is probably the answer..

many thanks

a

Chris C.

My engine compartment fan seems to be on all the time too. Of course, I am in Tucon AZ at the moment so...

Car just passed dealer inspection (several TSBs and a recall fixed) and they didn't see any malfunction. Let us know if you have a relay issue or just noramal operation. Thanks!

MUSSBERGER

Last summer I was at the glen and noticed that one of the guys from our local chapter's 987S had the fan running without the engine being on. Mine had never done that even after coming off the track and I told him so. He replied that It had always done that when it was hot.

akif

It does that when it's hot enough in the engine compartment.

Last year when it was 100+, after long drives it kept going on and off - even when the car was locked.

SleepRM3

Does the fan wear down the battery? Seems possible?

bet

Not during operation of the car, unless the alternator is not working properly. I don't think the original poster has a problem with the fan running after shutting off the car, just running constantly during operation.

Macster

all the time engine on, even while on the freeway. While I couldn't tell if it was running when driving the car at the speed limit as I slowed car down for an exit as the speed dropped down and tire/wind noise died down I could hear engine compartment fan running.

Ambient temperature IIRC 116 degs. F. and hotter than blue blazes. Engine intake air temperature was at some times over 135 degs. F. Even at highway speed it never got down to even ambient. Normally in milder weather intake air temperature at best gets no closer to ambient than 12 to 15 degs. F. and in traffic with hot air off of pavement, double or even triple that difference would not be out of the question.

With that high of an intake air temperature that indicates engine compartment temperature is real high as well. Engine compartment fan running all the time in low speed driving under high ambient temperature conditions would not surprise me, now. It was a bit troubling at the time because I had no experience with car in that kind of heat. Before, on real hot days (with temps approaching the low to mid-90s) many times I would leave Boxster parked and drive other car.

Even after shutting engine off as engine heat soaks engine compartment I could expect the engine compartment fan to kick on as engine compartment temperature climbed over some threshold.

Then after some time as engine lost its heat load, the engine and compartment would still be hot and upon engine start the engine compartment fan could kick on because the trigger temperature for this is different if engine off vs. engine running.

If engine compartment fan runs all the time even with engine off, or comes up when engine dead cold (though dead cold is a relative term and depends upon something less than 116 degs. F. in the shade and no shade...) then something's wrong. I'd suspect a failed engine compartment temperature sensor. Better if it fails to run fan all time vs. not at all and thus subject the engine/engine compartment to excessive temperature.

Sincerely,

Macster.

SleepRM3

How much heat from the engine transfers to the occupant space? Was just curious as to how hot the passgenger compartment gets with that kind of heat?

Macster

and insulation on wall separating cabin from engine compartment.

Some heat I'm sure soaks through but I've never had any problems from the heat coming through enough to even notice.

On a hot day, cabin hot simply because sun heats up all of car, top and windows, etc.

Car has great AC though and can bring cabin temperature down in no time and keep cabin cool...

However, that one time in AZ at 116 degs. F. I could not find an AC setting that seemed to generate much if any cool air.

I was a bit panicked because of the very high temperature and the heat various sensors were reporting as I was driving. I had a digital cooking thermometer I used to stick out window to check outside air temperature and an ODB2 code reader/data viewer I used to monitor coolant and intake air temperature. Any second I expected engine to seize from the heat.

(Back home gave heat readings to service advisor to pass on to Porsche factory with my concerns about possible heat damage. He got back to me that factory said if no overheat warning light on heat had no effect on engine. And I believe it, cause that was maybe 120,000 miles ago (car has just over 180,000 miles on it now) and engine has shown no signs of any ill effects from that experience or any other for that matter. Only recently did water pump (bearing) finally start making enough noise to require water pump replacement. And I attribute that to simply the water pump bearing wearing out. I do note however that from the 02 model on at various times Porsche has touted changes mainly of the aerodynamic kind to -- it claims -- improve cooling in extremely high ambient temperature driving conditions, and has also touted its testing in high ambient temperature conditions, mainly in South Africa.)

Anyhow, in my state I was probably -- with hindsight and time to reflect -- not thinking clearly (and maybe the damn heat had something to do with that!) and may not have chosen the best setting for the AC.

I've since learned -- experimenting driving car on very hot days at other times and in other locales -- that instead of setting the temperature to a low temperature setting instead setting the cabin temperature to a higher temperature though still lower than ambient seems to work better. The AC blows cool air and the cabin feels much more comfortable. And the AC heat exchangers do not preheat the air flowing through the radiators as much either.

That is, instead of trying to get cabin down to 72 degs. F. in 116 degs. ambient temperature setting AC temperature to maybe 80 degs. F. would see enough cool air to make the cabin seem cold in contrast to what's outside.

It may have been that hot day in AZ that July engine controller/AC controller turned off AC due to excessive heat... Better to subject driver/cabin to hotter temperatures than risk overheating engine.

Sincerely,

Macster.