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I think the basis for the 'myth' is the general problem of carbon buildup on some direct injection engines.
The first refutation of that on that is the fact no one owning an ST has had serious carbon buildup occur.

There ARE other brands of vehicles with a problem, but not the ST engine (nor the regular MK3 engine.)

So I agree no problem idling the ST..
(with the exception of doing it in extremely hot weather with the AC on full blast.. unless you are in the car and can see if it is over heating)
 

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food for thought...

other ford cars use the same motor and if they have an automatic transmission, there is an option for a factory remote start. therefore the engineers that designed this engine think that it is ok for the motor to idle for at least 15 minutes with no problems


but... excessive idling can be bad if you have colder spark plugs and they are not getting up to a high enough temp they may get fouled.
 

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Only way it may be bad is if you're idling for maybe an hour or more. Just adds wear and use that isn't being tracked on the odometer. But it is better than sitting unused for a year.
 

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You're fine. Idling any car is technically bad for it and of course bad for your wallet since you burn fuel, but if you aren't leaving your car idling for a long time or all the time then it won't make a noticeable difference with anything. Like @STraightNasty said, every cop in America who runs an ecoboost engine powered car sits along the road idling waiting for me to roll by too fast and pull me over.
 

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while I'm not saying this means its bad or fine...

keep in mind, cops do not own the cars, nor do they deal with any of the maintenance or have any concern with how long the engine will last. even if idling was the worse thing you could do to a motor, a cop would still keep the engine running while they sat there for as long as they needed to.
 

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Unless your sitting in your car waiting for someone no real reason to idle from a startup for more than a minute. Everything should be lubricated by that point and good to drive. Just drive reasonable until the water and oil come upto temp.

Sent from another galaxy.
Glad I'm not alone...a lot of my friends think I'm crazy when I tell them I don't let my car warm up for 10 minutes unnecessarily.

Now, when I have a girlfriend I will admit there have been times I've started it early to warm it up a little so they don't complain lol...but aside from that, nope. Usually when the RPMs drop from 1200 to the normal idle I'm off.
 

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Cleveland Area here, and I usually let it idle for 5 mins or so, just so I can get a little more warmth before freezing on my commute.. Strange thing happened this morning though when I got in after a couple minutes of letting it run in the driveway, the idle still hadn't dropped down like it normally does. Was still sitting at about 14/1500 RPM still.. Anyone know what the car uses to figure out when it'll drop its idle down? Something I should be concerned with?

It was a nice 5 degrees when I left this morning I thought my hand might freeze to my Anarchy Motive shift knob, gotta love the Ohio cold!
 

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Cleveland Area here, and I usually let it idle for 5 mins or so, just so I can get a little more warmth before freezing on my commute.. Strange thing happened this morning though when I got in after a couple minutes of letting it run in the driveway, the idle still hadn't dropped down like it normally does. Was still sitting at about 14/1500 RPM still.. Anyone know what the car uses to figure out when it'll drop its idle down? Something I should be concerned with?

It was a nice 5 degrees when I left this morning I thought my hand might freeze to my Anarchy Motive shift knob, gotta love the Ohio cold!
Yeah man this morning was TERRIBLE for us too. Wind chill had me feeling like it was -4 and car read 7...horrendous.

The car monitors oil/coolant temps and intentionally runs rich (high idle) to warm the car while it circulates the super cold, thick oil around. Oil pressure is ridiculously high for a while and warming the car up quicker with high idle helps speed the process of getting it to optimal quicker. Some days it's like 35 seconds (or when I leave work and it has a little bit of heat in it from the day) and other days like this morning it's a 2 minute process of waiting.
 

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Yeah man this morning was TERRIBLE for us too. Wind chill had me feeling like it was -4 and car read 7...horrendous.

The car monitors oil/coolant temps and intentionally runs rich (high idle) to warm the car while it circulates the super cold, thick oil around. Oil pressure is ridiculously high for a while and warming the car up quicker with high idle helps speed the process of getting it to optimal quicker. Some days it's like 35 seconds (or when I leave work and it has a little bit of heat in it from the day) and other days like this morning it's a 2 minute process of waiting.
Cool that's what I had guessed as well. Just threw me off with still idling high after a good 5 minutes, never saw that happen last winter but I guess it wasn't this bad last year either. Wish I had a heated garage for the poor girl!
 

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I think the basis for the 'myth' is the general problem of carbon buildup on some direct injection engines.
The first refutation of that on that is the fact no one owning an ST has had serious carbon buildup occur.

There ARE other brands of vehicles with a problem, but not the ST engine (nor the regular MK3 engine.)

So I agree no problem idling the ST..
(with the exception of doing it in extremely hot weather with the AC on full blast.. unless you are in the car and can see if it is over heating)
I have to completely disagree with this. I've seen a surprising amount of carbon build up after only 20,000 miles. There are plenty of scoped intakes you can refer to that show there's a serious problem with carbon buildup (at least on the US MK3/MK3.5). This just isn't true.
 

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Cleveland Area here, and I usually let it idle for 5 mins or so, just so I can get a little more warmth before freezing on my commute.. Strange thing happened this morning though when I got in after a couple minutes of letting it run in the driveway, the idle still hadn't dropped down like it normally does. Was still sitting at about 14/1500 RPM still.. Anyone know what the car uses to figure out when it'll drop its idle down? Something I should be concerned with?

It was a nice 5 degrees when I left this morning I thought my hand might freeze to my Anarchy Motive shift knob, gotta love the Ohio cold!
It was 4 degrees here in STL, and mine stayed at elevated idle for ten minutes while I defrosted it.

It has to look for a mix of light off temp for the Cat, and improving water temp, so idle can stick high for a while.

I mean with how this car can talk to itself, I would be surprised if it knew the defrost was on in super cold temps and wanted to help you out.
 
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It was 4 degrees here in STL, and mine stayed at elevated idle for ten minutes while I defrosted it.

It has to look for a mix of light off temp for the Cat, and improving water temp, so idle can stick high for a while.

I mean with how this car can talk to itself, I would be surprised if it knew the defrost was on in super cold temps and wanted to help you out.
I'm pretty sure it does. Let the car idle without defrost and it seems to "warm" faster and drop the RPMS in less time. All this fancy brain power anymore I wouldn't be surprised.
 
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