Fan on after shut down, how long?
 

Just wondering how long do your fans run after shut down?

Should I sit in the car and let it idle a bit before shutting it off?

It takes as long as it takes. Let the car decide.

LOL - nice answer Expo

+1. unless its staying on for hours at a time, let it do what it is meant to do

10 minutes.

it will shut off when the motor is cool enough just let it go i let mine go and just go in the apt...if you go out like 2 hours late and it's still on then i would go to a dealer but if it's like a couple minutes you're cool

haha, i remember, i was like WTF???? when this first happen, i love my 8

Well down here in the desert it can run for a long time. I park in the garage and it seems like an eternity before it shuts off. 10+ minutes on a regular basis.

^^ same here, its always FKN hot in texas....

Thats why I did like others did in the forum and went to an oversized aftermarket radiator, went as far as drilling relief holes in the tsat to get the needed water flow thats obviously killing engines time and time again from overheating. wirekit the fans to energize together helps, the hot climate here on the gulf coast sometimes gets brutal unforgiving, thats why I have a backup plan to releive the heat....CO2 cannistered shorts that deploy to cool my ass. heh it works........

Well, if you don't like the fan staying on when you shut off your car, go back, turn the ignition to ON (don't start the car) and back off, it'll stop the fan from running.

Not recommended. The fans come on for a reason. Just let them do their job.

I have yet to have the fan stay on it has been so cold this year... Some cars do this a lot and other's don't. Our Honda did it like a maniac and our Subaru never does it.

lol, there should be a sticky about this. Every person new to the 8 freaks out when that fan comes on. Its louder than when the car is running lol.

I freaked out more when Jiffy Lube did my oil and the differential was dripping all over my driveway. They didn't clean up the mess they left behind, I ended up going to the dealer about it too...

It's not as unusual as you may think. Occasionally the fan on my Miata—and on my '02 VW GTI—would stay on for a long time, too.

Doesn't every car made in the last 20 years do this already?

I freaked out when you said you took an 8 to jiffy lube period. :uhh:

Let the fans run they'll turn off. I wouldn't worry until the day they actually do drain your battery and you have to push start it. then I'd get a new battery.

Meh Mine will run for a few minutes :smoker:

the reason they stay on is because there is no water flow past the sensor when the engine is off - not an issue to turn the fans off that way if it annoys you .....

Don't ask, I was 120 mi from home and... :dunno:

with the mazsport fan mod, it turns on more often while driving so when i shut off it doesnt need to stay on for too long. usually less than 30 seconds even after hard driving.

It was my understanding that the water pump doesnt function if the car is off, therefore the fans coming on is pointless anyway. For this reason, I tend to run my car for a min or so after a hard run, and if I hear my fans on after I switch the car off, I turn it back on. Probably pointless :dunno:

Sitting there idling is just defeating the purpose. As everyone else has said, jut let it do its job - it knows when to shut off.

And yes, most radiator fans have been working this way since the fan belt went the way of the Dodo.

btw: my wife's iMac fan was running at high speed for a long time last night (cool indoor ambient despite our heat wave at the moment), but a simple SMC (ROM) reset did the trick. Horse of a different feather, but related.

Yesterday was the first time I heard mine run. Then again, it did set a new record here yesterday (101, ugh!). Kinda funny because I had just read this thread on Friday. Yeah, it's loud, almost as loud as the engine! Doesn't bother me; just funny to hear.

I've had mine come on once or twice for twenty seconds to a minute or so...never a long period, but I live in PA.

Umm, not quite. If it weren't performing a function, it wouldn't turn on. Power to the fan would simply be cut when you turn the ignition off. And whoever said that it doesn't do anything since the pump isn't running is wrong too. The running fan is, in fact, performing a cooling function. Turn it off at your own risk.

ooooo i'm really worried my motor will overheat when it is not running :lol:

Wow, that's one of the more ignorant comments I've read around here.

Just because your engine isn't pumping water doesn't mean that you wont get some amount of circulation due to convection. Furthermore creating a temperature differential in the radiator will lower core temperatures as the entire cooling system will always seek thermal equilibrium. It just won't happen as fast as if the water was circulating.

Engineers put a lot of thought into designing this engine, and even then many of their systems seem to underestimate the demands of the engine. If the engineers thought the cooling fans were required after the engine is shut off, do you really want to risk shutting them off, knowing their penchant for under-engineering things rather then over-engineering them? If anything I'd want to mod them to come on earlier and stay on longer.

perhaps you are too young to remember that once upon a time the fan was direct drive off the front of the motor . All the manufacturers must have changed to electric to stop them all overheating while not running :lol:

Seriously though lets think about why Mazda may have designed the system this way - I believe it could be to aid in certain situations when an engine is turned off for only a few minutes - ie going into the store to pick up the paper . In that situation there would be some benefit in leaving the fans on so that any heat soak in the engine will be rapidly cooled by the cooler radiator water upon restarting .
Anybody else have any decent suggestion other than the "Mazda did it that way so it must be right" BS ?

15 minutes on a hot summer day for me.

hehe when i first bought the car and got home and this happend i was like wtf? then i checked to see if the car was still on. lol

Oh you flatterer, I'm well old enough to have changed fan belts (when they were really fan belts).

Not so applicable to our [present] 8's, but there is some fuel injector vapor-lock prevention advantage to continuing to flow cooling air around the engine compartment after engine shut down on very warm days.

Otherwise as you cite, and I stand corrected in that you appear far from ignorant on the subject.

Who doesn't like a fan when they're hot, anyone, anyone? Leave the fan on, don't torture your baby :nono: !

Fan run-on time can be decreased if you turn off the A/C at least four minutes before you turn off the car. Keep the cabin fan running, but shut off the compressor with the A/C button. This alone will let the engine cool enough before shutdown to trim a few minutes off the time.

The 8 is smarter than most owners.... let it does what it wants.

Or you can turn your heat up full on a hot day JT. :)

Ol' days (pre-auto computers) we used to pride ourselves on being able to limp home regardless the malady. I've actually used the heater to offset overheating for a short duration.

Keep in mind that there's no such thing as cold - only an absense of heat. Think moving heat from one place to another. That's all a/c and radiators really do.