Idleing to warm up (rant?)

[15Michaeljoseph]

Well being that it was 15 degrees this morning... When it gets really cold, and I start my car, the PS pump whines like crazy for a little less than a minute... I let it sit usually until that stops.

Then when I get to driving it I get this harmonic whistling coming from what sounds like the tranny.

Hahaha 25 y/o cars plus winter: I'd say warming up via idle is the least of our worries

Sent from my XT1064 using Tapatalk

[Exodus_2pt0]

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).

You have open/closed loop confused, and you are mistaken on the conditions for each.

Closed loop doesn't activate until the coolant temp is near operating temp.

Point still stands, it is no where near the point of damaging the engine. The richest It will get is mid to high 13:1. No EFI engine is dumping so much fuel during open loop as to damage it, that would be a huge liability.

Finally, the mentality that letting your car idle to warm will damage it is new.

Get your shit straight.

[Streichholzschächtelchen]

My gf just bought one of those fancy new skyactiv mazda 3s and it is programmed to hold 1500rpm for about 45 seconds, then 1250, then 1000 from which it drops naturally to it's idle. They did that shit on purpose and it has me wondering. My dad always told me to let motors warm up if there are dissimilar metals involved they don't expand at extremely varied rates, but idle doesn't seem like the best solution. Pumps and shit are barely turning, alternator barely alternating, etc. I borderline want to install a "choke" on my car, an intentional air leak that I can turn on and off so it idles high before I hop in. For the time being I just cruise under 2000rpm when it's cold or sit in the car keeping it a little above idle til it's warm.

Mind you I run a hair rich at idle, 19lb injectors.

[nando]

You have open/closed loop confused, and you are mistaken on the conditions for each.

Closed loop doesn't activate until the coolant temp is near operating temp.

Point still stands, it is no where near the point of damaging the engine.

Finally, the mentality that letting your car idle to warm will damage it is new.

Get your shit straight.

no. I'm not confused. I don't need a lesson on EFI from you, either. lol.

Open loop is not the same thing as warmup. Open loop is only while the O2 sensor is too cold for any feedback, it has absolutely nothing to do with coolant temperature. Closed loop activates as soon as the O2 sensor is warm - with a heater, it only takes about 10 seconds. FYI, the M20B25 and M42 have an O2 heater (the eta doesn't).

Warmup mode lasts as long as the engine temperature is cold. Typically there's a warmup curve that starts at -40c and goes to about 70c. When you start your engine on a cold day, it can add about 50% more fuel, which tapers off as it gets warmer. Again, absolutely nothing to do with open loop. The warmup curve is accounted for in the O2 feedback loop too, BTW.

If you think that the BMW printed manuals in 1980 are new, which say do not warm up your car at idle, I don't know what to tell you.

[Exodus_2pt0]

Purposefully adding a vacuum leak during open loop would be a bad idea. During open loop (warmup or fault condition) the ecu is relying on preset data. If you introduce unexpected air it will not add fuel to compensate.

[nando]

My gf just bought one of those fancy new skyactiv mazda 3s and it is programmed to hold 1500rpm for about 45 seconds, then 1250, then 1000 from which it drops naturally to it's idle. They did that shit on purpose and it has me wondering. My dad always told me to let motors warm up if there are dissimilar metals involved they don't expand at extremely varied rates, but idle doesn't seem like the best solution. Pumps and shit are barely turning, alternator barely alternating, etc. I borderline want to install a "choke" on my car, an intentional air leak that I can turn on and off so it idles high before I hop in. For the time being I just cruise under 2000rpm when it's cold or sit in the car keeping it a little above idle til it's warm.

Mind you I run a hair rich at idle, 19lb injectors.

all cars run at a higher engine RPM when they are first started. a smaller engine will have a bigger delta than a larger engine. on the M20 it's only a couple hundred RPM.

[nando]

Purposefully adding a vacuum leak during open loop would be a bad idea. During open loop (warmup or fault condition) the ecu is relying on preset data. If you introduce unexpected air it will not add fuel to compensate.

OPEN LOOP IS NOT WARMUP!

repeat after me... :p

[Exodus_2pt0]

Open loop is only while the O2 sensor is too cold for any feedback, it has absolutely nothing to do with coolant temperature. Closed loop activates as soon as the O2 sensor is warm

You are wrong.

[nando]

You are wrong.

I'm not. I have the Bosch EFI documents that say otherwise. I've also been tuning standalones and stock computers for the last 10 years. what do you have?

[Exodus_2pt0]

Plenty of factory training across multiple platforms.

The ecm looks for more than O2 cycling to switch to closed loop. Also, once it is is closed loop it can only maintain 14.7 AFR because that's the only time narrowband sensors are accurate. So it switches back and forth from richer/leaner to maintain 14.7. In reality what you are saying would just further my point. If it switches to closed loop right after startup, then it's not running rich.

Closed loop is specifically for maintaining a 14.7 AFR during low load conditions for the most efficient burn. Open loop is used during conditions where certain sensors can't be utilized, and during wot conditions where a narrow band sensor is useless for AFR monitoring. High load is when the afm or MAF step in.

Unless of course BMW did it differently from any other manufacturer. Which if they did, I'll stand down.

Also, please, let's not turn this into a e-dick measuring contest. Standalone ecms are nothing like a factory ecm that is regulated by Federal standards. I didn't get my automotive knowledge from the internet so spare me the condescending bullshit, k?

[nando]

Plenty of factory training across multiple platforms.

The ecm looks for more than O2 cycling to switch to closed loop. Also, once it is is closed loop it can only maintain 14.7 AFR because that's the only time narrowband sensors are accurate. So it switches back and forth from richer/leaner to maintain 14.7. In reality what you are saying would just further my point. If it switches to closed loop right after startup, then it's not running rich.

Closed loop is specifically for maintaining a 14.7 AFR during low load conditions for the most efficient burn. Open loop is used during conditions where certain sensors can't be utilized, and during wot conditions where a narrow band sensor is useless for AFR monitoring. High load is when the afm or MAF step in.

Unless of course BMW did it differently from any other manufacturer. Which if they did, I'll stand down.

I'll dig up that Bosch document at some point. it's from the same period as the E30.

[e30onBBSs]

It definitely says not to let it idle to warm up, I read it in an e36 manual and was like whoa

[Exodus_2pt0]

It says that due to emissions regulations. Nothing to do with damage to the vehicle.

[nyChris]

If you have the Owners handbook, refer to page 48. It states "It is not recommended to allow the engine to warm up at idling speed. Drive away at moderate engine speeds immediately after starting".

They claim the reason not to idle your car to warm it up is excess carbon buildup at idle. Fuel washing off the oil on the cylinder walls does not appear to be the basis of their recommendation.

[mrsleeve]

Depends on the rig, You ever deal with a diesel, when its cold out???? You dont want to put a heavy work load on them until, they have some heat in them thanks.

In the warmer months its fine to jump in and let the oil pressure come up and take off. But when its very cold out, You want to let the oil get a little temp in it. Its been a long time but I have seen broken ring lands and broken rods from putting too much load on a stone cold 0*f engine right out of the gate, growing up on the farm as a kid in both gas and diesels

Yes idleing to warm up is not a issue other than emissions laws (in many cities its ILLEGAL to idle for more than a couple of mins to when not actively driving) and building up of carbon in the intake track and the combustion chamber surfaces (thank you EGR systems). The carbon build up is an even bigger issue in the new modern direct injected engines since there is no fuel to wash and cool a the intake valves and the stupid EGR that runs nearly constantly