Cool Down Procedure?

[dreamrider22]

So I'm a new owner.

Took the car out for a quick drive the other day to run an errand. 5 minutes there, 5 minutes back, didn't push the car, just cruised.

When I got back home, I noticed a lot of heat coming from the hood and from the front kidney grilles. I assumed this was normal given how powerful the engine is, but it was also surprising b/c its not like I was coming from a 24 hour track day.

Is there a procedure that you guys use to cool down the car after a drive?

Like leave it outside for a bit before bringing it in the garage or setup fans (I saw this on an M5 thread).

Thanks!

[arucano]

The main reason for the fans running after you turn the car off is for the turbo cooling. The fans will always run for a few minutes. If you were "pushing" the car, it will take a little longer. It is always a good practice to idle the engine for a few minutes after a hard run to allow the turbos to cool down a little before shutting the engine off.

[MMMM6GC]

Just to add my 2c: firstly I seldom take short drives as i found it usually takes a good 10-15minutes to get the engine up to operating temp. I make sure to keep it under 3-4k rpm during this time.

As for cool down as @arucano mentioned, after a more spirited drive I tend to let the car idle a couple minutes before shutting her down. During hotter months, when I bring the car inside the garage I'll open the hood and the leave the garage door open for bit to let heat escape. I'm usually working in/around the garage so on really hot days I might run a box fan pointed at the engine bay, with hood and garage door open.

This mf'er gets seriously hot, even in winter when I bring the car inside and shut the garage door, it'll up the ambient temp by up to 10f!

[FinalRenegade]

I tend to drive softly approaching home, no hard launches off the line, no pushing it and I'm accelerating softly to decrease the strain on the engine. Once I back it into the garage I just shut it off knowing I've had a cool-down drive on the way home. On hotter days I take my leaf blower(dedicated to drying the car) and go to town on the engine bay lol

Also I notice a weird sound coming from the passenger side of the engine bay for a few minutes after the car shuts off, feels like a low metallic hum, anyone know what that is? does not sound like the front radiar fans...

Sometimes its there, sometimes its not hmmm, this is a very young car : 16K Miles

[LJohnson32]

Given that you are a new owner I figured it may be beneficial to share warm up information as well.

My cooldown procedure is basically a reversal of my warm up procedure which is:

1. Start engine, allow to idle down before putting in gear
2. First 3-5 minutes, very gentle load, short shifting to keep RPM's below 2k even. Engine in Efficient to keep as much load as possible off the cold engine, and to keep the water pump idle, allowing the engine to reach temp faster
3. 5-10 minutes, still gentle load but allowing RPM's to creep up above 2k to 2,500
4. Once the oil temp needle creeps off the bottom 160 hash - switch to Sport Plus to allow the water pump to run full time. Gentle to moderate (50% throttle MAX) load up to 3k until engine is at full operating temp (~195F for me)

Cooldown for last ~5 minutes of driving:

1. Remain in Sport Plus for better cooling via the water pump running full time
2. Short shift and coast as much as possible (similar behavior to #2 above but in Sport Plus rather than Efficient)

By the time I park to shut off, if I followed the above properly it should be around 185-190F which is about as cool as you can hope for. I try to do as much of the cooldown while driving to promote airflow rather than just sitting at idle and having the engine heat soak a little. I find that if I were to do that after the above mentioned 'driving cooldown', the engine will actually gain temp slightly. Just my OCD hard at work

[debauch]

There’s no specific mention or special procedure in the manual for cooling down the car. I can understand not driving hard until the car warms up but unless you’re tracking, park it, turn it off, walk away.

[jjasonSU]

Just park it. If the fans need to run they will continue for a while

[dreamrider22]

Really appreciate the responses all.

Based upon your insight, I'm going to implement a bit of each of your suggestions. I'm just glad that the heat being generated is normal b/c it's not something I was use to in cars.

[castlesteve]

I have a box fan hanging on the wall in front of the car. I generally do a cool down for a couple miles/minutes and then pop the hood in the garage and let the box fan take the car down to room temp. It will save on dry rot for years to come

[dreamrider22]

Originally Posted by castlesteve

I have a box fan hanging on the wall in front of the car. I generally do a cool down for a couple miles/minutes and then pop the hood in the garage and let the box fan take the car down to room temp. It will save on dry rot for years to come

Great advice, thank you!

[talos]

I'm a new one like you. I was scared by the heat of this guy. I had to open the hood to let the heat from the turbine escape as soon as possible

[castlesteve]

To be fair, i've been doing the box fan method since the early 90s. I had 200k miles on an original 944 Turbo and it pulled strong. Heat kills turbo cars, and manufacturers would never tell you to do all this extra work.... but you should.

[danielgmanm6]

I just got back from a night ride where I was really pushing it. Like everyone mentioned, I take it easy back home to cool it a bit and don't cut it off right away. If it's not too hot out I like to put the heat on for a couple minutes. I haven't owned the car during the winter months but can already tell it's going to have the best heat ever. Heat was coming out an easy 90f lmao.

[arucano]

"Cooldown for last ~5 minutes of driving:
Remain in Sport Plus for better cooling via the water pump running full time"

The M6 has a belt driven pump. The pump runs continuously while the engine is running. All temperature control is done via the thermostat. I agree totally with the "go easy until it reaches operating temperature"

[LJohnson32]

Originally Posted by arucano

"Cooldown for last ~5 minutes of driving:
Remain in Sport Plus for better cooling via the water pump running full time"

The M6 has a belt driven pump. The pump runs continuously while the engine is running. All temperature control is done via the thermostat. I agree totally with the "go easy until it reaches operating temperature"

Interesting - the reason I noted this was due to monitoring the water pump speed with BimmerLink, the 'target RPM' value for the water pump alternates periodically between 0 and 250 in Efficient and Sport, whereas in Sport Plus it remains at 250.

Regardless of how the car does it, Sport Plus does keep the car operating cooler than the other modes

[arucano]

The cooler circulating pump for the turbos are electric indeed. The main pump is mechanical belt driven. I did not realize that Bimmerlink gave the speed of the electric pump.

Found this info on the determination of turbo coolant pump running time:

Activation of the electrical turbocharger coolant pump takes into account the following variables:

Coolant temperature at engine outlet
Engine oil temperature
Injected fuel quantity

The injected fuel quantity is used to calculate the heat contribution to the engine. The after-run of the turbocharger coolant pump can last up to 30 minutes. To improve the cooling effect, the electric fan is also switched on. The electric fan runs down for a maximum of 11 minutes.