Hi,
I just noticed that the fan doesn't come on when I park the car anymore. The turbo water pump still goes on for a minute or so. Is this simply because the engine isn't hot enough to need it?
Just wandering if the colder air temps are the reason for this, as it used to always come on for a couple of minutes.
Josh

 

They don't even come on during stop-go traffic? or when the temp reads almost third white mark?

 

It always came on until about a month ago. I drive it most at night, which is aroung 50 degrees here. My temp gauge never exceeds the second from bottom bar.

 

Try letting it idle until the temp goes up a bit, that is where the fans would kick in. Just take care, if the fans don't kick in, the car would overheat

 

The fan switch is a separate switch than the one for your gauge in the car. It is unlikely that both of them would be sending out a low signal at the same time. You might want to check the connections on the back of your thurmofan switch (the one that controls the fans). There is two levels on it. At one temp it turns on the first fan and the second mark it turns on the second fan. I believe (but don't quote me on this), only the second (high temp) fan stays on after the car is off. After the sensor comes down off that high mark and the car is off the fans turn off.

The thurmofan switch is located on the radiator at the drivers side just under the top inlet hose. It should have a few wires coming out of it. Check for loose connections.

 

Clarck's Garage has instructions for testing fan switch. Prey that it's OK...otherwise prepare for a HG failure.Don't ask how I know...

 

??? Thurmofan switch and HG failure ??? I could see warping the head due to overheating but what else is there to tie the two problems together, or is that what happened?

 

Yep.It goes like this:No fan-->coolant temps rises from normal-->heat soaks and softens the HG (cyl#4 is in the danger zone b/c coolant flows and heats from front to rear)-->then you add some boost,1,2bar/18psi,seem to be enough,and presto! ,white cloud of smoke when flame ring gives up because of soft HG behind it. Then,of course,if you use metal HG,this problem is does not exist.
The head itself does not warp,or mine did not,there's not necessarily enough heat for that.
Local Official Porsche Shop's mechanic's first question was " Does fan work,is switch OK?" when I went there... When I said that it didn't boil or overheat he said that it doesn't need to.Apparently the usual story is that customer comes in and complains that the fan doesn't work,he's told that besides the switch the HG needs to be changed.No comprendo b/c "It didn'overheat and it's expensive.",but after a couple of weeks the vehicle is towed back...
BTW,I didn't then notice failed fans ,I now I watch them over-eagerly.
The good news was that I had a reason to make complete overhaul to the head & ignition system and had injectors cleaned at the same time.

 

Silverbullet:

I literally just had a similar problem to this: my radiator fans wouldn't turn off, no matter what the temp of my car. There is a thermo switch on the drivers side of the radiator just below the big radiator hose, and that can break in either the on or off position. I just removed my airbox and similar componentry, and using a 29mm deep socket stuck my arm down in there from up top and took it off and put the new one in, managing to only spill a cup or so of coolant. I'd try it.. lindseyracing.com sells the part for 10 bucks...
http://www.lindseyracing.com/Merchan...=944ELECTRICAL

Good luck