[Alberta]

Originally Posted by GranitM5

+1. After a spirited or long drive, I park it and let it run for another 10 minutes before shutting her off.

10 minutes seems a lot...

After a drive, I personally let my car run for 3 minutes.

[AHall]

Originally Posted by Can-am

10 minutes seems a lot...

After a drive, I personally let my car run for 3 minutes.

Do you still hear fans after shutting down when your car has run for 3 minutes at idle?

[Alberta]

Originally Posted by AHall

Do you still hear fans after shutting down when your car has run for 3 minutes at idle?

Sometimes I do, but it is not systematically the case.

[dawidk1978]

Originally Posted by GranitM5

+1. After a spirited or long drive, I park it and let it run for another 10 minutes before shutting her off.

10 m idle running = shortage of life v8 engine. V8 engines doesn't like idle running

[Jamesmick]

Along these lines, years ago I added a Greddy Turbo Timer to a car to which I had added a turbo and a bunch of other mods. Does anything like that still exist and would it address the concerns people have?

I don't usually let mine warm down too much at idle since it takes me a few minutes to squeeze it into my garage. I figure that's enough time to let the oil run through stuff. The car does run the fan afterwards though for a while.

[GranitM5]

Originally Posted by dawidk1978

10 m idle running = shortage of life v8 engine. V8 engines doesn't like idle running

Never thought about that but I let the car run for 5-10 minutes on start up to warm up the internals. Don't see it shortening the life of the engine and anyway I don't keep a car that long.

[GranitM5]

Originally Posted by Can-am

10 minutes seems a lot...

After a drive, I personally let my car run for 3 minutes.

5-10 minutes give or take.

[FatRear08]

95% of the time my fans run on shutdown 5-7 min depending on how hard I drove. I did notice the other day that when I arrived home after a 30 minute drive, which was hard at times, I let it idle in the driveway for about 5 minutes because I had to move some things out of the garage. When I pulled in and shut her off, the fans did not kick on. I’m no scientist but maybe the 5 min at idle cooled it to the point that it saw no need to keep them on???

[Fantastic 5]

I've heard that you should do that, but who has the time???

[Alberta]

Originally Posted by FatRear08

95% of the time my fans run on shutdown 5-7 min depending on how hard I drove. I did notice the other day that when I arrived home after a 30 minute drive, which was hard at times, I let it idle in the driveway for about 5 minutes because I had to move some things out of the garage. When I pulled in and shut her off, the fans did not kick on. I’m no scientist but maybe the 5 min at idle cooled it to the point that it saw no need to keep them on???

I doubt it.

An engine running at idle tends to heat more because there's nor air to cool the radiators.
When I was ridding dirt bikes I've learned that the engine was getting cooled while riding at low speeds.

The only reason I let the engine running for 3 minutes after each drive is to keep the turbos lubricated.

[Alberta]

Originally Posted by Fantastic 5

I've heard that you should do that, but who has the time???

Letting your engine run 2-3 minutes after a drive is not gonna kill your day!

[Resjudicata]

Originally Posted by bpma

Even after short, slow rides (quick commutes with kids, etc), once I turn off the engine the engine fan runs noticeably loud, for a few minutes.

Is that normal? I understand it would need it after a highway run, or flooring it a bit, but after a quick, regular commute?

Is that normal?

It's the turbo cooling down. The longer you're in sport mode or reving to push that turbo boost; the longer it will take to cool down.

You can't really disable the turbo; but the "softer" you coast home, the better chance you have for cooling the turbos. But it doesn't really matter, it doesn't hurt anything.

[spuntyb]

Yes. My 2019 Comp does this every time I drive it, short or long trips. Like landing the space shuttle

[Rams01]

TTT can confirm: even after BMW replaced a cracked coolant expansion tank, my 2020 M5C will still sit there with fans on sometimes for 10 minutes after a spirited drive. Very interesting car; annoying it has that 165mph limiter

[omgmike]

Originally Posted by AHall

I have less than 300 miles on a 2021 M5C. I went for a ride around several highways in Dallas for about 2 hours. Nothing crazy just highway speeds and then service road driving with stop lights closer to home. I monitor oil and water temperatures and no signs of a problem. I do not hear the fans running after I get home and turn the car off. Anyone with a 2021 hear fans running after car is shut off.

My '22 does it a lot. I originally thought it was a built-in turbo timer to keep the oil moving through the turbos to cool them down, but I guess it's the fan? My brother's old RX-7s (FDs) had aftermarket turbo-timers for exactly that reason, to keep the oil flowing for a few minutes, long enough to cool the turbos down.

[omgmike]

Originally Posted by Resjudicata

It's the turbo cooling down. The longer you're in sport mode or reving to push that turbo boost; the longer it will take to cool down.

You can't really disable the turbo; but the "softer" you coast home, the better chance you have for cooling the turbos. But it doesn't really matter, it doesn't hurt anything.

That's what I thought it was -- basically a built-in turbo timer. You used to have to install after market versions to cool your turbos, nice that it's factory these days.

[AHall]

Originally Posted by omgmike

My '22 does it a lot. I originally thought it was a built-in turbo timer to keep the oil moving through the turbos to cool them down, but I guess it's the fan? My brother's old RX-7s (FDs) had aftermarket turbo-timers for exactly that reason, to keep the oil flowing for a few minutes, long enough to cool the turbos down.

Do you live close to a highway? I have to drive for 15 minutes on service roads and neighborhood streets before getting home. So I am guessing my car is already cooled before I get home

[omgmike]

Originally Posted by AHall

Do you live close to a highway? I have to drive for 15 minutes on service roads and neighborhood streets before getting home. So I am guessing my car is already cooled before I get home

Sort of? US 290 is the main road out where I live, but it's not a freeway. It's about 5 mins from my house to 290.

[Resjudicata]

Originally Posted by omgmike

That's what I thought it was — basically a built-in turbo timer. You used to have to install after market versions to cool your turbos, nice that it's factory these days.

Definitely. Comfort or eco will be cooler than sport or sport plus. But it's built in. Also the grille active open and close.
I wish I had a video after my track day showing how it opened, cooled and then closed, while I was out of the car.

[CFoote]

The engine runs hot. It's just cooling down...Hence why we have multiple batteries in the car.

Chris

[omgmike]

Originally Posted by Resjudicata

Definitely. Comfort or eco will be cooler than sport or sport plus. But it's built in. Also the grille active open and close.
I wish I had a video after my track day showing how it opened, cooled and then closed, while I was out of the car.

That would be super cool to see!

[Maverik259]

Clearly no one here watches racing. Lol. You should t let the car just sit idle to cool down. No different than just Letting the fans do their things. And as a few have stated it's not good for the engines to idle.

Ideally you should drive at stable low rpm higher speed for 5-10 min. This allows the engine to cool without high stress. If you ever watch a race particularly F1, you will see they all go for 1-2 laps for a cool down. They aren't driving slow mind you either. But they drive fast enough to get good air flow but don't stress the engine or spool the turbos too high. I typically come out of M1 and let the engine run in "eco" mode for the last bit of my drive home. This lets the engine run at lower RPMs and prevents spool up of the turbos uneccesarily. Don't get me wrong this won't 100% prevent the fans as they kick on based on coolant temp that we don't have access to monitoring.