Idleing to warm up (rant?)

[e30onBBSs]

Okay so I used to believe this same notion "let it warm up at idle or else it's bad for the engine because it's cold". Do most car people know this? Do you know it's bad for the engine?

Someone on here corrected me one time and I still didn't believe him until I asked one of my teachers and he said otherwise, which lead to further reasearch. I then told my friends from school and they just called me stupid, when I posted links to articles, forums, etc.

Am I the only one who knows it's unneccessary and detrimental to idle your car to warm it up???

[E30 Wagen]

Only in the past couple years did i learn it's bad to let a car idle too long when it's cold, something about it running rich and washing the oil from the cylinders? It still doesn't stop me from letting my car idle for a bit when it's 0 degrees and I need to scrape ice of the windshield.

[Exodus_2pt0]

It isn't going to hurt anything.

I saw an article that argued it would run rich until it was up to temp. The only reason it *might* run rich is due to open loop. Even then, you aren't in danger of washing the oil off the cylinders until you dip into the 9-10:1 AFR range, which just isn't going to happen.

I let my cars warm up before driving when it's super cold. The better the oil flows to and from my turbos during a load, the happier they are.

I would be much more concerned about a high load scenario with cold, thick oil than sitting idling.

Seriously, mountain out of a molehill. Plus, I like getting into a hot car rather than freeze my ass off.

[Northern]

could run rich for catalyst heating purposes as well, unless your car predates cats/EFI.

I usually just peg limiter until it reaches optimal temp. Less time spent cold can't be a bad thing.

[e30onBBSs]

It isn't going to hurt anything.

I saw an article that argued it would run rich until it was up to temp. The only reason it *might* run rich is due to open loop. Even then, you aren't in danger of washing the oil off the cylinders until you dip into the 9-10:1 AFR range, which just isn't going to happen.

I let my cars warm up before driving when it's super cold. The better the oil flows to and from my turbos during a load, the happier they are.

I would be much more concerned about a high load scenario with cold, thick oil than sitting idling.

Seriously, mountain out of a molehill. Plus, I like getting into a hot car rather than freeze my ass off.

I learned it runs rich, takes forever to warm up, and is worse than a normal load (low rpm) because the oil pressure is relatively bad at idle. And oil gets everywhere within 15 seconds, so since the cars are fuel injected it is better to just drive and get it up to temp where the engine is much more effecient quickly, rather than slowly at idle.

Also cats don't work well at idle, nothing else gets warmed up besides the engine, and it wastes $.

I like getting into a warm car though! I think there are pros and cons and that it's not going to blow an engine or drastically lower it's life but is worse, maybe others will chime in. From what I've read and heard from my teacher who is a whiz about cars I still believe the car is OK to drive and probably better off.

[Stanley Rockafella]

With the advancements of lubrications (synthetics especially), I see no need to idle anymore.

You save time, fuel and there's no negligible difference in powertrain wear.

[Exodus_2pt0]

I agree, the need to idle isn't there.

This new mentality that it is "bad" for an engine to idle while warming up is only from an emissions standpoint. You are not going to have any mechanical issues arise from letting your car idle an warm up. OTOH, if you get in it and beat on it, you might.

Again though, if you have a turbo, keep it in vacuum until it gets up to operating temp.

The point I'm trying to make here, is that it just doesn't matter. If you are more worried about pinching pennies for gas, then hop in and go. Personally, I have no problem burning fuel for comfort.

[Kevinl]

Its going to run rich whether it is idling or driving while cold.

I don't purposely idle my car but if it super cold or hot as hell I will let it run a bit to make the interior more tolerable before getting in

[rturbo 930]

I don't idle my cars to warm them up, partly because it isn't needed, and partly because I usually need to leave ASAP. I do take it easy while they warm up though. Generally keep revs to about 3k max, and light throttle (maybe half?). Which kinda sucks since my daily has a whopping 90hp, and I have a bit of a lead foot.

[e30 gangsta]

My e30 runs like shit when its cold, I assume due to it being a stroker with big injectors etc running on the stock motronic. I suppose if I went ms the cold start would be better.

[modernist]

Yeah cold running with stock Motronic is pretty meh. It already struggles to idle smoothly at all due to the batch fired injectors, the engine being cold doesn't help

[MF DOOM]

It isn't going to hurt anything.

I saw an article that argued it would run rich until it was up to temp. The only reason it *might* run rich is due to open loop. Even then, you aren't in danger of washing the oil off the cylinders until you dip into the 9-10:1 AFR range, which just isn't going to happen.

I let my cars warm up before driving when it's super cold. The better the oil flows to and from my turbos during a load, the happier they are.

I would be much more concerned about a high load scenario with cold, thick oil than sitting idling.

Seriously, mountain out of a molehill. Plus, I like getting into a hot car rather than freeze my ass off.

All this. I live at 7000ft in WY and it gets fucking cold. If I have to get in and go I take it real easy and keep it in vacuum.

Also, it would take some real studies to convince me that your car would be running rich enough to wash the oil off the cylinders. I just cant see it in an oe car.

[nando]

Okay so I used to believe this same notion "let it warm up at idle or else it's bad for the engine because it's cold". Do most car people know this? Do you know it's bad for the engine?

Someone on here corrected me one time and I still didn't believe him until I asked one of my teachers and he said otherwise, which lead to further reasearch. I then told my friends from school and they just called me stupid, when I posted links to articles, forums, etc.

Am I the only one who knows it's unneccessary and detrimental to idle your car to warm it up???

RTFM. it says right in there not to let it idle. Start it up and drive away. Just don't beat on it until its warm.

Motronic's warmup works just fine BTW - to the person who said it doesn't work well due to batch fire, that makes hardly any difference at all. You just have a 25 year old engine that likely needs a bit of work.

[nando]

I agree, the need to idle isn't there.

This new mentality that it is "bad" for an engine to idle while warming up is only from an emissions standpoint. You are not going to have any mechanical issues arise from letting your car idle an warm up. OTOH, if you get in it and beat on it, you might.

Again though, if you have a turbo, keep it in vacuum until it gets up to operating temp.

The point I'm trying to make here, is that it just doesn't matter. If you are more worried about pinching pennies for gas, then hop in and go. Personally, I have no problem burning fuel for comfort.

It's not a "might" it's an absolutely - it runs rich because fuel atomizes poorly in a cold engine. This is done on purpose, it has nothing to do with closed loop (which is only for the few seconds when the O2 sensor is cold). Even a modern super efficient car still runs rich when cold (they also do it to heat up the cats faster).

And the mentality isn't new. Unless you think 35 years ago when BMW and other manufacturers started using EFI is new.. again, RTFM.

[ccsdo5]

I think the richest my turbo car idles at is like 12-12.5 AFR when cold. Which is basically the same under boost. I start and idle my toyota tacoma in the morning because it is cold at 5:45 am here in NY. That thing has like 212,000 miles on it so I'm sure letting it get warm enough for me to sit in isn't the end of the world.

I mean you don't really need to warm cars up any more with efi and all that, but if you look at new honda's they have the exhaust manifold incorporated into the head so the car heats up faster, gets into CL faster and has better idle AFR's. Also these new car use like 0w-20 oil so even when it's cold and idling I'm not really concerned with oil pressure. I would be more concerned about running a car with a low temperature thermostat, or stuck open thermostat.