Idle and fan on off?

TallguY · 02-07-2002, 08:02 PM

Ok today I noticed after I took my car for a bath and shine while at idle the fan was engaging for about 5 seconds and the shutting off. when the fan came on the idle increased by about 200 rpm give or take. This was after normal driving conditions on a 35 degree day. I never noticed this before and was wondering if this is normal. the temp gauge on the dash was reading a temp where it usually sits. this would continue to happen for what seemed to be as long as i let the car sit a idle. I didn't time it but it seemed to cycle the fan ever 1 or 2 minutes.

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Steven Saunders · 02-07-2002, 09:22 PM

don't know if this helps, but when I had my MY99RS I had a alarm system installed and the people didn't install it correctly to the ecu. CEL was on and the fans were cycling on and off every 5 seconds.
Steve

vtfan · 02-07-2002, 09:56 PM

Mine does this too. I've always thought it strange that the fan only comes on for a few seconds. If the engine really is hot then the fan should at least run awhile until it cools the engine down.

KGreb · 02-08-2002, 11:51 AM

This sounds like normal behavior to me.
My guess here is that the ECU turns on the fan when coolant temps reach a certain setpoint, then turns off when it drops below. With cold ambient temps and idling you probably were right at the set point, so the temp dropped pretty quick when the fan kicked on.
Also, if the suby temp gauge is anything like any of the newer cars I've driven, it's highly non-linear. My miata reads the same position on the factory gauge from about 80C to 108C.

Aprilia Jon · 02-08-2002, 04:42 PM

Your fans turns on/off with the A/C independent of the coolant temp in order to deal with the added heat/load. If you have the A/C on to clear the windshield of moisture or something (I realize it is winter but you can have it on with the heat) then the fans will cycle on-off rather quickly. Your A/C pump will also cycle quickly because it only works until a certain A/C temp is reached and then turns off. It turns back on when the temp raises back up. Hence quick cycling of the fans.

Jon

02-07-2002, 08:02 PM	#1
TallguY Scooby Newbie Member#: 13875 Join Date: Jan 2002 Location: Naperville Vehicle: 2002 WRX Wagon Silver	Idle and fan on off? Ok today I noticed after I took my car for a bath and shine while at idle the fan was engaging for about 5 seconds and the shutting off. when the fan came on the idle increased by about 200 rpm give or take. This was after normal driving conditions on a 35 degree day. I never noticed this before and was wondering if this is normal. the temp gauge on the dash was reading a temp where it usually sits. this would continue to happen for what seemed to be as long as i let the car sit a idle. I didn't time it but it seemed to cycle the fan ever 1 or 2 minutes. * Registered users of the site do not see these ads.

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02-07-2002, 09:22 PM	#2
Steven Saunders Scooby Newbie Member#: 563 Join Date: Nov 1999 Location: Cumming, GA, USA Vehicle: 2002 Subaru WRX WR Blue Pearl	don't know if this helps, but when I had my MY99RS I had a alarm system installed and the people didn't install it correctly to the ecu. CEL was on and the fans were cycling on and off every 5 seconds. Steve

02-07-2002, 09:56 PM	#3
vtfan Scooby Newbie Member#: 13961 Join Date: Jan 2002 Location: Outside of Atlanta Vehicle: 2002 WRX Wagon Platinum Silver	Mine does this too. I've always thought it strange that the fan only comes on for a few seconds. If the engine really is hot then the fan should at least run awhile until it cools the engine down.

02-08-2002, 11:51 AM	#4
KGreb Scooby Newbie Member#: 13463 Join Date: Dec 2001 Chapter/Region: TXIC Location: Houston, TX Vehicle: 2005 LGT 2004 FXT	This sounds like normal behavior to me. My guess here is that the ECU turns on the fan when coolant temps reach a certain setpoint, then turns off when it drops below. With cold ambient temps and idling you probably were right at the set point, so the temp dropped pretty quick when the fan kicked on. Also, if the suby temp gauge is anything like any of the newer cars I've driven, it's highly non-linear. My miata reads the same position on the factory gauge from about 80C to 108C.

02-08-2002, 04:42 PM	#5
Aprilia Jon Scooby Newbie Member#: 13394 Join Date: Dec 2001 Location: Austin TX Y'all Vehicle: 2001 GC8 Coupe Silver	Your fans turns on/off with the A/C independent of the coolant temp in order to deal with the added heat/load. If you have the A/C on to clear the windshield of moisture or something (I realize it is winter but you can have it on with the heat) then the fans will cycle on-off rather quickly. Your A/C pump will also cycle quickly because it only works until a certain A/C temp is reached and then turns off. It turns back on when the temp raises back up. Hence quick cycling of the fans. Jon