fan will not cut off after shutting car off?
06-06-2008, 09:46 PM
#4
Today it was 91 degrees and the wife and I went up to an RX8 meet.
After parking the car, we went to get ice cream (spent roughly 5 minutes waiting), and when I got back to the car, the fan was still running.
It eventually shut off not too long after I got back to the car.
So like swoope said, running time depends on the temp.
After parking the car, we went to get ice cream (spent roughly 5 minutes waiting), and when I got back to the car, the fan was still running.
It eventually shut off not too long after I got back to the car.
So like swoope said, running time depends on the temp.
06-06-2008, 10:35 PM
#5
perhaps an understanding of why it stays on would be a help ....
You have a temperature sensor that switches the fans on and off . They might come on at say 98deg C but they won't switch off till the sensor sees say 92degC . There is a good reason why they do that - it prevents too many on/off cycles of the fan .
When you stop the motor and the fans are already running - it can take a long time for the temp at the sensor to get below the switch point because there is no water circulating past it . The fans are cooling the water in the radiator but not the water by the sensor .
Hope that helps
You have a temperature sensor that switches the fans on and off . They might come on at say 98deg C but they won't switch off till the sensor sees say 92degC . There is a good reason why they do that - it prevents too many on/off cycles of the fan .
When you stop the motor and the fans are already running - it can take a long time for the temp at the sensor to get below the switch point because there is no water circulating past it . The fans are cooling the water in the radiator but not the water by the sensor .
Hope that helps
06-07-2008, 08:54 AM
#7
The fans on my bike do the same thing but it never runs very long. last night after a short drive mostly freeway when i shut the car off the fans kept running but after approx 5 min they were still running. temp at shut off was 198. tonight i will grow some ***** and let it run till ither the battery dies or it shuts off. I did figure this was normal but the length of time it runs is what concerned me.
Maybe it's cause i park in the garage and the air circulation is cut from the front of the car?? I does get wicked hot in there after driving.
Last edited by Mr.&Mrs.Magic; 06-07-2008 at 08:56 AM. Reason: spelling
06-07-2008, 09:03 AM
#8
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Kinda silly, but I'm in Florida and after I get home from driving it pretty hard on a +90F day and parking in a small one car garage, I will go ahead a pop the hood for awhile to help with cool down. Even without popping it, I think the longest I ever had the fans run after shut off was about 3-3 1/2 minutes.
I now have the Mazsport cooling fan mod, so the reality is........even if it is on at shutoff, it goes off within about 30 seconds now. That mod kicks the fans on a ~195F and cuts them back off at ~180F, so according to my scanguage.......I NEVER see anything higher than 198F. Fans cycle at idle(with the air on) a little more than I would like, but ya can't have everything.
I now have the Mazsport cooling fan mod, so the reality is........even if it is on at shutoff, it goes off within about 30 seconds now. That mod kicks the fans on a ~195F and cuts them back off at ~180F, so according to my scanguage.......I NEVER see anything higher than 198F. Fans cycle at idle(with the air on) a little more than I would like, but ya can't have everything.
Last edited by Mazurfer; 06-08-2008 at 06:36 AM.
06-07-2008, 06:26 PM
#10
If it runs too long.
Check the fans when the car is cold. Jack it up. Rotate fans.
One fan may be bad causing the car not to cool properly, hence the fan stays on longer when stopped.
Check the fans when the car is cold. Jack it up. Rotate fans.
One fan may be bad causing the car not to cool properly, hence the fan stays on longer when stopped.
06-08-2008, 10:05 AM
#12
Registered
Like others have said, most cars these days do this. Not all. My wife's '86 Accord did not, and her '94 Camry does not. My '87 Accord and (of course) my RX-8 do. My wife panics every time she hears one of those running, no matter how many times I explain.
Ken
06-10-2008, 03:14 PM
#13
ok i guess i just needed to wait a little longer. timed it today and it ran for 6 min and 12 sec. I think my car is running a little hotter than it's supposed to. The AP is showing a temp of 195 or there about while on the freeway. I did the TB bypass mod today and noticed the one of the rubber gromets from the air box is missing. I think i rember reading somewhere that if you lose them the car will over heat. Any truth to this?
06-10-2008, 05:08 PM
#14
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I suppose if a grommet fell into a fan and jammed it, you could see an overheat.
Interesting memory jog: when I did the throttle bypass mod, I pulled the airbox and noticed one of the grommets was missing. I had just bought the car new a few days before, so it seems that either the factory also has difficulty installing this piece or somebody at the dealership was messing with it.
Interesting memory jog: when I did the throttle bypass mod, I pulled the airbox and noticed one of the grommets was missing. I had just bought the car new a few days before, so it seems that either the factory also has difficulty installing this piece or somebody at the dealership was messing with it.
06-10-2008, 05:15 PM
#15
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The lower grommets are WAY to soft for their location and EASILY push through the holes. I replaced them with the grommets that held the engine cover in place and they haven't moved at all since.
If a grommet gets pushed through it could jam in the fan and burn the motor out, causing a blown fuse and/or overheating.
The only way to tell for sure is to dig underneath the battery and intake and physically inspect the fans for damage.
If the fans you heard running were as loud as, if not louder then the engine at idle, both of your fans are probably working just fine.
You can jiggle the key to force the fans to turn off, but in a car known for not handling heat very well, do you really think that it is a wise thing to do? I don't.
Let the car cool down in the way it was designed to.
If a grommet gets pushed through it could jam in the fan and burn the motor out, causing a blown fuse and/or overheating.
The only way to tell for sure is to dig underneath the battery and intake and physically inspect the fans for damage.
If the fans you heard running were as loud as, if not louder then the engine at idle, both of your fans are probably working just fine.
You can jiggle the key to force the fans to turn off, but in a car known for not handling heat very well, do you really think that it is a wise thing to do? I don't.
Let the car cool down in the way it was designed to.
06-10-2008, 05:31 PM
#17
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last summer I had been driving for about an hour in 112 degree weather. Got home, fans ran for bout 10 minutes.
Now with the AP maps, I expect they won't run as long (since the temps stay cooler) but we'll find out in the coming months.
Now with the AP maps, I expect they won't run as long (since the temps stay cooler) but we'll find out in the coming months.
06-10-2008, 05:37 PM
#18
I have your fans set to come on at 185°F and on full at 195°F
So, when you turn your car off, the temp will spike and the fans will stay on until the temps get below that. (It isn't a time-based thing.)
Here in Phoenix, they will sometimes run for 10 or 15 minutes after a hot shut down. Maybe even longer, so don't drive on a crappy battery.
The factory thresholds are 207°F and 214°F, which is WAY too hot IMHO.
If you want, I can raise them to somewhere in the middle like 195°F and 205°F for low and high respectively.
So, when you turn your car off, the temp will spike and the fans will stay on until the temps get below that. (It isn't a time-based thing.)
Here in Phoenix, they will sometimes run for 10 or 15 minutes after a hot shut down. Maybe even longer, so don't drive on a crappy battery.
The factory thresholds are 207°F and 214°F, which is WAY too hot IMHO.
If you want, I can raise them to somewhere in the middle like 195°F and 205°F for low and high respectively.
06-22-2008, 09:01 PM
#21
I just bought my 8 about 3 weeks ago, and although here in the SF Bay Area we rarely get hot weather, we did for a few days. I drove it to work on Friday, 7 miles each way on surface streets in 95 F. weather, and the fans were off when I shut off the car, but by the time I got to my front door they came on. I didn't remember reading about it in my owner's manual (I did read it cover to cover) so I went back out and turned it on for a minute, let the idle drop as far as it always does i.e. 700, and when I shut it off the fans did not come back on.
I will open the hood every time for a few from now on, if I've driven for more time/distance/or in high heat. Thanks for this thread!
I will open the hood every time for a few from now on, if I've driven for more time/distance/or in high heat. Thanks for this thread!
