Buck

I was at an autocross today and noticed the engine compartment fan was running well after I had shut the engine off. A couple of minutes later I noticed it had cut off. It caught my attention because I don't remember hearing it run after the engine was off. It continued this behavior all afternoon. When I took it off the trailer several hours later (ran the motor maybe 2 minutes) the fan ran for over ten minutes and I finally disconnected the battery. After 30 minutes I re-connected the battery and the fan still came on.

Any ideas? Wiring harness?

Viken

My fan always comes on minutes after I shut the engine off. In the summer, it does the same but even more often. I always thought that was normal because I've had other cars that did the same.

993Widebody

I've noticed this happen in the summer or after a hard DE session or autoX. I always thought this was normal, never checked to see how long it stayed on - but don't believe it is more than 15 minutes or so.

Randall G.

It is normal for the fan to run, to help cool the engine when it's "very" warm. However, it ought to stop running once the engine has cooled.

I guess you need to verify the rear blower is not running when your engine is stone cold, or running so long that it drains your battery.

Best of luck!

JimBob Jumpback

[quote]Originally posted by Buck:
<strong>I was at an autocross today and noticed the engine compartment fan was running well after I had shut the engine off. A couple of minutes later I noticed it had cut off. It caught my attention because I don't remember hearing it run after the engine was off. It continued this behavior all afternoon. When I took it off the trailer several hours later (ran the motor maybe 2 minutes) the fan ran for over ten minutes and I finally disconnected the battery. After 30 minutes I re-connected the battery and the fan still came on.

Any ideas? Wiring harness?</strong><hr></blockquote>

Bubba,

Der be sumtin veree rong wit ur porch kar. u shud sellin it befur itz blowed ups on u. sins we iz pratically naybours, i wilst giben uz $500 fer it. dat is reele us monee, knot kornfaderate monee.

Yur fren,
JimBob

Bob-SC 98C2S

Buck,

I agree with the comments, the fan coming on is normal. Mine does it after its been driven especially during summer. I would not disconnect the battery, but I would check to see if it comes on after the car has cooled down.

It does get hot in SC.

Bob
Aiken, SC

Berkley

I don't know about the 993, but in the 964 C2, after running thru the mountains for an hour or two in plus 90 degree weather, there would be a delayed fan operation for 15 to 20 minutes when garaged....thought the manual indicated that was normal <img src="confused.gif" border="0">

Terry Adams

I had a Fiat 128 whose fan ran on, and people were always telling me that I left my engine running.

Mike J

Hey, thats funny, long time ago I had a 128 Sport as well (a Fix It Again Tony!). I had the same comments...one time they paged me because my car was still running!

Buck

Update:

I hooked the battery back up and the fan came on but after about a minute it slowed down and then turned off. It appears from the general concensous in this thread that the fan is suppose to run after the engine is off. My next question is, does it have two speeds? Mine seems to run at two speeds. The slower of the two speeds isn't very noticeable but the high speed is pretty load and moves enough air to blow leaves in the driveway.

I'm going to keep monitoring the fan operation as I think I may have an intermitent problem because I know I've never heard the fan on high speed before.

Hank Cohn

Buck:

When my wiring harness went bad, my engine fan would run continuously. This was only one of the symptoms my car displayed; however, mine would not stop running at all. I had to disconnect the battery, like you did, but as soon as I would reconnect it, it would continue to run even after starting the engine. Other initial symptoms for my car were and injector nozzle that remained open and, in the end, the starter motor would not disengage as it continued to run.

Hank

Randall G.

Good morning Buck,

The rear blower definitely has two-speeds. You can make the rear blower run in slow-speed by turning the climate control temperature **** to (about) 21C or higher. That is, the rear blower runs in slow-speed to supply heated air to the cabin.

I believe the engine cooling function is limited to fast-speed, but I could be wrong. Maybe it will run in slow-speed, as well?

Rocket

I have never heard this fan operate on my 993. I appreciate it is cold and wet on our sodden shores but occasionally the temperature does rise above 90. Is there a simple test to check the operation (like the oil cooler fan test bridging terminals of the relay), and is it of major concern if its not operating correctly?

Rocket

Randall G.

Hey Rocket,

You can test the rear blower in the same way you test the A/C condenser & oil cooler blowers.

At the plug for the rear blower relay (sorry, don't know the number) in the engine fuse box:

slow-speed = #3 to #7
fast-speed = #3 to #5

An easier way to check the slow-speed blower .... as I wrote above, just turn on your ignition, and run the temperature control **** to &gt; 21C. The rear blower should start in slow-speed.

I don't know how to test the automatic engine cooling fast-speed function--short of getting the engine really hot. Furthermore, I don't know what the setpoint (rear blower temp. sensor) is for starting the blower (I don't think anyone does ).

Robin 993DX

Buck,

The fan noise you heard is from the engine aux. blower. The aux. blower serves two purposes, (1). Pushes the air through the heat exchanger to provide heat for the interior of the car. (2). Blow air to take out excess heat built up from the engine when it is not running.

In your case with the engine off the aux. fan was preprogrammed to turn on at 75 degree Celcius, and off at 70 degree Celcius. The temperature is determined by the temperature sensor located at the heater duct intake area ont he left side of the engine.