its liquid cooled, right?

[maurice1]

Originally Posted by litnin

Although 99.9% of the people don't and won't do this, that is a good idea.

It doesn't matter if it's your car or bike, it's "better" if you pull up
and let your car idle for 15-30 seconds before shutting it down.

When you just pull up, park, and shut down, your cooling system
will get a temperature spike. Pulling up and idling for a few minutes
helps the cooling system temperature stabilize and prevents that spike.

Generally, it won't cause any short term damage, but over a long period
of time, it can give your cooling system a little bit more time between part failure.

Thanks for the tip! I didn't know.

maurice

[Freedom]

Originally Posted by litnin

Although 99.9% of the people don't and won't do this, that is a good idea.

It doesn't matter if it's your car or bike, it's "better" if you pull up
and let your car idle for 15-30 seconds before shutting it down.

When you just pull up, park, and shut down, your cooling system
will get a temperature spike. Pulling up and idling for a few minutes
helps the cooling system temperature stabilize and prevents that spike.

Generally, it won't cause any short term damage, but over a long period
of time, it can give your cooling system a little bit more time between part failure.

Maybe you mentioned it before Litnin, I know that that there was a post about this several years ago. It's a great point and something I always do as well. Usually on a hot day after taking it slow through the sub, by the time I pull in front of the garage the fan kicks in and I'll let her idle until it stops.

[Graybush]

Thanks. The first couple of times I didn't hear it until I shut down but I've started listening for it lately.

[tubes_rock]

Just a question, litnin:

In a car this makes good sense. It allows the coolant to circulate, radiator to dissipate heat, etc, etc.

On a motorcycle, the fan only runs when the coolant is too hot. I have only heard my fan run when the bike is sitting still. So, is it better to pull in and shut the engine off (since the bike was moving just prior to that and pushing air across it's heat dissipating members) or let it sit idling for a while and get hotter and hotter for a few minutes.

It seems to me that my bike is cooler when it's moving and hotter when it's not, so letting it sit and heat up before shutting it down sounds counter-productive.

Maybe I'm not seeing something...

--Justin

[thunderglass]

I always allow mine to idle for a few minutes to let the turbo cool down after running it hard..............no wait that's my lawn mower.

[Easy Rider 2]

Originally Posted by tubes_rock

Maybe I'm not seeing something...

If you feel the need to question something 'Litnin has said, it should be obvious that you have overlooked something...........

If you were riding hard right up to the time you turned into the driveway, then I agree with him.

If you were cruising along at 40 mph or below for the last mile or so......I'm pretty sure you would gain nothing and the overall temp might actually go UP if you sit idleing with the fan off.

[litnin]

Originally Posted by tubes_rock

Just a question, litnin:

In a car this makes good sense. It allows the coolant to circulate, radiator to dissipate heat, etc, etc.

On a motorcycle, the fan only runs when the coolant is too hot. I have only heard my fan run when the bike is sitting still. So, is it better to pull in and shut the engine off (since the bike was moving just prior to that and pushing air across it's heat dissipating members) or let it sit idling for a while and get hotter and hotter for a few minutes.

It seems to me that my bike is cooler when it's moving and hotter when it's not, so letting it sit and heat up before shutting it down sounds counter-productive.

Maybe I'm not seeing something...

--Justin

Justin, your cooling system on your car is no different than that on the bike.
The fan on your car doesn't (or I should say, *shouldn't*) run at highway speeds for the same reason... air is moving across the radiator.
The fan on your car will only run when it reaches the maximum allowable
temperature... same with the bike.

But the same principle applies.
The radiator dissipates heat whether air is moving across it or not.
If you pull up and shut it down, your circulation stops and all "under load"
heat is now percolating in the engine and cooling system.
The it has to rely on the coolant to thermally conduct through itself to
pass the heat to the radiator.
If the pump is still pumping, the system is still bringing taking the hot
coolant to the radiator.
When you are under load, no matter if you are idling under load or
actually under load, you are producing more heat than you are at idle.
When you come to a stop, your cooling system surges.
By idling for a short period of time, you reduce that back-lash of
heat that surges (it doesn't surge as hard, but it will still surge).
The only true way to keep it from surging is to have an electric pump
that will continue to circulate the coolant until the it's cold (without the engine running).

The thing is to gauge your engine load before shutting down.
If you were out carving the canyons, then you want to let it idle for
a bit longer.
If you were puttering through your neighborhood at 10-15 mph,
then you can reduce the time.
You are absolutely right... it will come to a point where the coolant
will start to get hotter from sitting.
You just have to gauge your engine load and adjust your idling (cool down time) accordingly.

[litnin]

Originally Posted by thunderglass

I always allow mine to idle for a few minutes to let the turbo cool down after running it hard.............

Idling a turbo motor is absolutely CRUCIAL for the longevity of the turbo.

I can't tell you how many people I have talked to and how many instances
I've seen where people buy turbo charged vehicles and end up having
the turbo go out after 30-35k miles.

Idling for a turbo is all about oil pressure though...
People don't understand that even though that turbo isn't singing
when there's no load on it, it could still be spinning 10-15k RPM, even though
it's not making boost.
When you pull up and shut the engine down, you just pulled oil pressure
away from it.... then people end up having to replace their turbo or
have it rebuilt because the bearings fail.

[tubes_rock]

Makes sense. The idea being to even out the hot spots, even if the overall temperature itself isn't decreased, the hot spots are, and thus everything cools uniformly when the engine is shut down.

Makes sense to me!

Thanks!

--Justin

[maurice1]

i may have to change my screen name to overlycautious, but i am now a little confused. At first i thought the idea was just to make sure after a ride to let fan turn off if it was on at the time one stopped. After reading a few more posts, looks like depends on hard ride vs less hard ride will determine how long one waits to turn off bike. Did not sound like fan on or off was the determinant. A little clarity please. thanks

overlycautious