Fan Question
08-06-2009, 07:28 PM
#16
Happened to me a couple days ago for the first time ever. If I remember right --- I noticed it while turning off the car with the key in the ignition set as above. When I turned the key all the way off the fan went off -- back to the position just before cranking -- on. So I left it on for a bit. It was a warm day, running around 9 o'clock also (cycling low-speed oil cooler fan.)
08-06-2009, 11:13 PM
#20
Nordschleife Master
It happens to mine after I get off the track, runs for about 5min.
When I get home from a good drive, I open the deck lid, then turn the key to the "on" position & let the fan fun to pull out some of the hot air.
When I get home from a good drive, I open the deck lid, then turn the key to the "on" position & let the fan fun to pull out some of the hot air.
08-06-2009, 11:15 PM
#21
Three Wheelin'
The fan in my car runs for a few seconds after I have turned the car off and walked away, The first time I was like WTF? Then just figured that was the norm, I'd say on hotter days my fan turns on and off several times in the first 15 minutes after I park my car?
08-06-2009, 11:34 PM
#22
Noodle Jr.
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I shut the car off then turned the key back on and no fan.
08-07-2009, 12:46 AM
#23
Rennlist Member
From my memory there's a temperature switch in the engine compartment that cuts the fan on. Mine runs about 5 seconds then shuts off. The key does not have to be in for it to work. It usually does this anywhere between 1 and 3 times in a 10 minute or so period. Other than high ambient temp, mine cuts on after an extended drive as well. The first time was when I drove my car back 800 miles after the purchase. It cut on while I had my back to the car and scared the sh** out of me. When the fan relay picks up there's a loud click and an even louder fan. I don't see the temp switch info in my owner's manual. I may have seen it in the 993 maintenance manual. Don't quite recall where I read about the operation.
08-07-2009, 12:59 AM
#24
Seared
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I wonder if this has something to do with that short, dangling wire section coming off of the vacuum actuator on your air pipe. I asked you about it and you stated that it's always been like that.
Andreas
Andreas
08-07-2009, 01:24 AM
#25
Noodle Jr.
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08-07-2009, 01:35 AM
#26
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One thing to note is the engine blower fan has different high/low speed operation depending on whether the key is in the run position or not.
When the key is in the run position, the thresholds are much lower - thus the observation by some that the fan will run with the key in the on position.
Adrian Streather's book has good info on the fan logic. Also there is some engine blower activity if you put the temp dial all the way to the red it should also come on (not sure on the duration though)
I do this with my 993 after driving, and pop the engine lid for peace of mind.
From an old post:
https://rennlist.com/forums/993-foru...questions.html
When the key is in the run position, the thresholds are much lower - thus the observation by some that the fan will run with the key in the on position.
Adrian Streather's book has good info on the fan logic. Also there is some engine blower activity if you put the temp dial all the way to the red it should also come on (not sure on the duration though)
I do this with my 993 after driving, and pop the engine lid for peace of mind.
From an old post:
Hi Mike,
The rear blower operates in the following modes:
-To supply heated air to the interior when the temp. **** is set greater than ~21C, ignition on.
-At 45C, the blower starts in slow-speed to cool the engine, ignition on.
-At 62C, the blower starts in fast-speed to cool the engine, ignition on.
-At 75C, the blower starts in slow-speed to cool the engine, ignition off.
So ... after the engine is nice and hot, turn it off, then turn the ignition back on (don't start the engine). You should hear the rear blower start--either in slow or fast-speed.
Of course, if the engine is really hot, you'll hear the blower operate after you turn off the engine. I believe it's rare for the rear blower to run with the ignition off--pretty much limited to tracking the car and super hot days.
One more tidbit. By disconnecting the rear blower temp. sensor, ignition off, the rear blower should start in slow-speed and run continuously.
Hope this helps ....
Edit 12/19/02:
While helping someone diagnose their poor heat, learned something. His rear blower operated fine when heat was commanded by the temperature control ****, but the rear blower didn't start when the temp. sensor was unplugged, ignition off. Text from my e-mail to him:
**************
"I think your blower/sensor is fine here, and I've learned something. To be honest, a few other people have 'failed' the disconnect with ignition off test, with otherwise okay systems. Went out to my own car a short while ago, and I'll be damned if disconnecting the sensor didn't start the fan. Now, I and others have done this several times without trouble. Took the car for a drive, bringing engine temp. up to close to the 8:00 position. Disconnected the temperature sensor again, and after about a 5 second wait, the rear blower fired up. So .... apparently, the engine must be warm for this test to work. I guess my engine was warm the other times I've tried this.
I'll add that nowhere in the shop manual does it say that disconnecting the rear blower temp. sensor will cause the blower to run in slow-speed. Just like it doesn't say that disconnecting the oil cooler temp. sensor will cause the oil cooler fan to run in fast-speed. Purely empirical observations.
Considering that your own car has already passed the temperature control **** tests, the rear blower temp. sensor plug test doesn't tell you much. But, feel free to try it again with the engine warm."
****************
The rear blower operates in the following modes:
-To supply heated air to the interior when the temp. **** is set greater than ~21C, ignition on.
-At 45C, the blower starts in slow-speed to cool the engine, ignition on.
-At 62C, the blower starts in fast-speed to cool the engine, ignition on.
-At 75C, the blower starts in slow-speed to cool the engine, ignition off.
So ... after the engine is nice and hot, turn it off, then turn the ignition back on (don't start the engine). You should hear the rear blower start--either in slow or fast-speed.
Of course, if the engine is really hot, you'll hear the blower operate after you turn off the engine. I believe it's rare for the rear blower to run with the ignition off--pretty much limited to tracking the car and super hot days.
One more tidbit. By disconnecting the rear blower temp. sensor, ignition off, the rear blower should start in slow-speed and run continuously.
Hope this helps ....
Edit 12/19/02:
While helping someone diagnose their poor heat, learned something. His rear blower operated fine when heat was commanded by the temperature control ****, but the rear blower didn't start when the temp. sensor was unplugged, ignition off. Text from my e-mail to him:
**************
"I think your blower/sensor is fine here, and I've learned something. To be honest, a few other people have 'failed' the disconnect with ignition off test, with otherwise okay systems. Went out to my own car a short while ago, and I'll be damned if disconnecting the sensor didn't start the fan. Now, I and others have done this several times without trouble. Took the car for a drive, bringing engine temp. up to close to the 8:00 position. Disconnected the temperature sensor again, and after about a 5 second wait, the rear blower fired up. So .... apparently, the engine must be warm for this test to work. I guess my engine was warm the other times I've tried this.
I'll add that nowhere in the shop manual does it say that disconnecting the rear blower temp. sensor will cause the blower to run in slow-speed. Just like it doesn't say that disconnecting the oil cooler temp. sensor will cause the oil cooler fan to run in fast-speed. Purely empirical observations.
Considering that your own car has already passed the temperature control **** tests, the rear blower temp. sensor plug test doesn't tell you much. But, feel free to try it again with the engine warm."
****************
08-07-2009, 02:56 PM
#29
Noodle Jr.
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