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View Full Version : Winter Mornings; Idle? Up and Out?



Majo
01-20-2015, 06:44 AM
Having a debate with some friends, about idling in the morning versus getting in the car and going

So, what I do, is I let my car idle with the heat on for about five to ten minutes, then I just drive it out. My coolant level hits mid by then. I drive and keep the car under 3k for a bout 20 minutes after though

but

my friends say its best to just drive it out and let the engine heat up that way and to keep it under 3k

So, AZ members, what do you prefer?

4rings2turbos
01-20-2015, 06:55 AM
Personally I'm in the drive it almost right away camp. Since I'm a 2.7T I get reasonable acceleration keeping it below 2k RPM, so that's what I do. I almost never let my car idle, though occasionally if it's suuuuper cold out and I make a stop shortly into my trip I will let the car run so I only have one cold start instead of multiple before the engine has come to full temp.

This is a good debate, I'd like to know if there is any hard science.

RoadRage
01-20-2015, 06:57 AM
Start the car. Let it idle for 30 secs. to a minute. Go.

Try to drive at a constant rpm under boost until things warm up a bit. Usually a few minutes.

The only reason to let a car idle for a long time is to warm up the inside so you and/or your passengers are warm. Or because you're an asshole and you go 0-100 as soon as you leave the driveway.

HedonismBot
01-20-2015, 06:57 AM
Really depends on your commute I think. If you live 15 seconds away from the freeway on ramp and there's no traffic then you should let it warm up a LITTLE bit for safety's sake. Trying to merge with fast traffic on a cold engine can be dicey.

In terms of comfort it also depends on how cold it gets. I lived in Northern Alberta for one winter and it was common practice for everyone to go out to their car 30 -40 minutes before quitting time to turn their cars on. It's colder than Mars there though.

seanf86
01-20-2015, 07:02 AM
It all depends on temperature, -10-20 usually a few minutes then drive slowly, if its colder than -20 I let it run until the auto hvac kicks the fan up to the 2nd notch otherwise I can't shift into 2nd gear. I never idle for a long time unless its snowing out, I always start the car then proceed to clear/scrape the windows then it should be ready to go by the time I'm done and I always wait until the high idle goes away if the car is high idling.

MacFady
01-20-2015, 07:58 AM
I just let it idle for 30-45 seconds and then drive away grandma like for 2-3 minutes until up to temp, regardless of the outside temperature.

The "high idle" will be there when it's cold, I wait for it to drop before leaving, shortly after the SAI pump stops. If it is extremely cold say -20 to -40 C then the car will low idle right from the start so keep that in mind, still wait 45 seconds or whatever, but there will be no idle drop off in extreme cold. Owners manual says don't idle, drive away for what it's worth.

In my mind, driving will at least get everything up to temp in 2-3 minutes even if it's -40, idling just drags the wear and tear on for a long time, sometimes really long. I'm sure around here lately you could idle for 30 minutes and the car would not be up to temp. Last week it was so cold that I came up to a longer set of lights after 5 minutes of driving and my temp. started to drop back off again.

I also don't agree with waiting longer if you live near the freeway, mainly because your diff fluids etc. will still be bone cold and you're trauncing on it because your temp gauge is up to normal. Grandma's merge on the freeway just fine, take your time getting up to speed and the next thing you know everything is good to go.

jackpot1992
01-20-2015, 08:18 AM
On an old car I had, the manifold cracked from start and go...so I try to sit 1-2 minutes, just so the exhaust system and everything gets a little heat...probably a different story if you don't have a cast iron manifold though. I like to play it safe either way.

rodgertherabit
01-20-2015, 08:39 AM
pretty sure the owners manual says to just drive it...

crazexr7
01-20-2015, 10:55 AM
Owner's manual says not to let it idle

BaseDrifter
01-20-2015, 10:58 AM
Letting the car idle to warm up is just a good way to waste gas and run the car rich for an excessively long period of time. Start the car, wait 3-5 seconds for oil pressure to build, and drive. I stay out of boost until the engine is up to temperature though, and I also don't live in a super cold climate.

Rodgman15
01-20-2015, 11:05 AM
It's a B5 A4 get on that sumbitch!

But in all seriousness, here in Fargo where temps can be consistently -20 for weeks on end with no wind, I just stay out of boost until the oil temp is good and warm.

clumsyme
01-20-2015, 11:21 AM
It all depends on temperature, -10-20 usually a few minutes then drive slowly, if its colder than -20 I let it run until the auto hvac kicks the fan up to the 2nd notch otherwise I can't shift into 2nd gear. I never idle for a long time unless its snowing out, I always start the car then proceed to clear/scrape the windows then it should be ready to go by the time I'm done and I always wait until the high idle goes away if the car is high idling.

It only take you that much of a warm up to get into second?! I can only smoothly get in once the oil temp gauge has started to rise.

seanf86
01-20-2015, 11:24 AM
It only take you that much of a warm up to get into second?! I can only smoothly get in once the oil temp gauge has started to rise.

it depends on the windchill and how fast it sucks the heat out of the car sometimes its better, sometimes worse. Just filled the trans with 2qts MT90 1 qt MTL and its pretty good.

clumsyme
01-20-2015, 11:25 AM
it depends on the windchill and how fast it sucks the heat out of the car sometimes its better, sometimes worse. Just filled the trans with 2qts MT90 1 qt MTL and its pretty good.

Im sorry what is MTL?

seanf86
01-20-2015, 11:27 AM
Im sorry what is MTL? Redline MTL, its basically a thinner version of MT90. I called and spoke to Dave at Redline and he said I should have no problems running the mix.

clumsyme
01-20-2015, 11:28 AM
Redline MTL, its basically a thinner version of MT90. I called and spoke to Dave at Redline and he said I should have no problems running the mix.

OHHHH thats good to know. Because mine is horrible shifting into second until it is all up to temp

Looks like I am doing another trans flush

adam044
01-20-2015, 01:58 PM
Letting the car idle to warm up is just a good way to waste gas and run the car rich for an excessively long period of time. Start the car, wait 3-5 seconds for oil pressure to build, and drive. I stay out of boost until the engine is up to temperature though, and I also don't live in a super cold climate.

This is what I do. Although I do live where it's cold. Been 0 a couple mornings. Start and go.