As someone who lives in a really cold area, once it gets below a certain temp cold start gets reactivated. There's a second cold start sequence for the properly cold temps
That is actually more % on the enrichemnt side. If you start the car in -30* celsius enrichment is somwhere around 180-220% and will sound loud because duh, gasses :)
This is good. For the longest time, with previous cars, I thought starting the car and letting it idle was an ideal way to warm the car and get the oil and coolant to temp... especially during the winter in CT. My local indy shop, with BMW master techs, have actually told me letting the car idle after a cold start is terrible for fuel injected engines. They have seen issues with idling and adverse effects on the cylinders/cylinder walls that can actually contribute to more engine wear. I've heard this in other places as well. As soon as the car is started and the RPMs fall from the cold start, my wheels are rolling. Biggest thing is, I stay out of the boost and under 3K until the oil gets to temp.
Letting it idle for several minutes isn’t gonna damage your cylinder walls lol and if the injectors fail they were already bad in the first place, you’ll just have horrible gas mileage by letting it idle
So far so good on mine as well. The one annoying thing was even when the car was warm the car would still do a cold start every time. For example go to get a quick coffee or something after driving for 20min already. It goes in the same cycle. So I disabled it. Thanks for the video, good as always :).
I am by no means a mechanic but my understanding of cold start is that ECU just opens wastegate 100% and all exhaust is routed directly to downpipe bypassing turbo, that's why it is so annoyingly loud (turbo is no longer muffling the exhaust) and this way catalytic converter is getting warmer faster since all exhaust energy is directed on it without warming up turbo. If at cold start you press on gas pedal a tiny bit, just as much so that ECU feels it, the wastegate gets closed and the car becomes much quieter. I can see wastegate open status on my AK Motion data display. As soon as cold start phase is over (after about 1 min) ECU closes the wastegate. So as I understand the main idea of the cold start is mostly to warm up the catalyst as soon as possible.
N55 coldstart is fine. It only cycles when really cold. Not all the time like b58 does. Did you turn off coldstart with catted downpipe or do you run catless?
i don't mind the cold start but wish they'd implemented a system where once the cars up to a certain temp it didn't do the cold start if you start the car again
The manual for the m235i did say that for best fuel economy to drive the car right after starting the car up, and that you dont need to wait for it to "warm up". Like you said, seems like best way to warm up the car is to drive it. Love the videos!
Because when you let a car sit and idle, all you're doing is wasting gas. That's why a lot of states and countries have made it illegal to let your car idle due to the emissions.
@@kern417in germany its even illegal to drive around with ur car for no reason. Just cruising around is against the law. Let alone letting your engine idle when starting or in summer when u have the AC on in a Parkinglot, people will come up to you knock on the window tell you to turn off your engine. Much more worse here than in NA.
I live in Canada and I have had the cold start off for over a year now and there has been no issues! on really really cold days the car will disregard the no cold start and cold start, I assume as precautionary reasons. all in all no complaints and I highly recommend
Interesting. So when the temperature is extremely cold and the car has been sitting say all night and you have turned off the cold start via your tune or Carly etc. The car Will cold start as if it wasn’t coded off?
@@QuantomsJune top end a little bit yes, but you have to be WOT to really feel the difference. Otherwise nearly negligible. My next upgrade is a biger turbo that'll perhaps be more noticeable
My b58 heats up pretty quick, and I hate having neighbors close but if I move or it gets real freezing out I might turn it on. Also a side note, not having a cold start and then noticing I had one after a dealer service is the only way I knew they flashed it back to stock and I had to put my stage 2 back on
I’ve had cold start off for about going on 1 years and half . Reason why my cars is way to loud to be cold starting at 5 in the morning. As of right now no problems but I do let the car sit for like 10 mins . I’ve noticed when I’m really really low on gas the idling sometimes sometimes is rough almost as if the car was cammed lol
I have cold start off. I drive out of garage everyday at 5am. I let car idle for about 1-2min. This is at the start of the day. If going in and out of a store I will start driving when I’m ready. With my cammed camaro we had cold start off but would Let idle about 3min at the beginning of the day to allow proper piling on the cam and lifters.
One comment and one question: - whilst I agree that it is not doing anything for the engine to wait “5 minutes”, the other extreme - cranking and straight on the throttle is definitely not healthy IMO! I ALWAYS wait for the cold start phase to be over before I drive off, since that’s those 20-30 seconds in which I sincerely believe the engine needs to circulate fluids, warm up cylinders and pistons to some minimum operating temp, etc. As a mechanical engineer, I have yet to see a machine which enjoys being stressed whilst absolutely cold. Note - cold start phase is not equivalent to “putting the engine under load”. Even under load you will never hear the engine make the same noise at 1200 RPM. It is a different procedure. - How about “Start-up roar”, GTS/Porsche style? I always wonder if that introduces any risks on our engines, when programmed by a tune…
As a mechanical engineer, warming up the engine quickly is key. If you leave the engine to idle, it is spending more run time at lower temperature than it would if you drove the car. Gts roar is negligible. It only raises the rpm momentarily
@@kern417 I believe you are focusing on one extreme (you keep referring to “5 minutes” or minutes in general), whilst you ignore another - driving off within the first 2 seconds! No machine and no structure appreciates load right away. Cold loading also increases the risk of LSPI, especially for tuned vehicles. So it is all about balance. My personal formula is ~20-30 seconds which coincidentally is the cold-start, warm-up phase. Plus as you correctly stated - moderate RPMs until the engine gets to somewhat operational temps.
@@kern417 Besides the noise, any downside with the wear on the car (engine) by keeping the cold start OEM and startup roar (flash option in MHD) on a catless setup, while using good judgement until proper oil temp warmup (for me that's about ~10 minutes of babying the RPM/boost)? I suppose the cold start delete can be considered on the catless DP.
Fantastic,I thought it was just me who was paranoid about turning cold start off! Thank you for finding out and explaining everything 👍 But now the follow on question Kevin- how the hell does the engine replicate being under load?
I heard coldstart is important if you have a 8HP ZF Auto Transmission because it heats up that Transmission fluid better so that it doenst jerk from 1st to 2nd hardly when cold. Anyone can confirm that?
I turned mine off when i went stage 2. I used a 200 cell CAT rather than going completely CAtless. I heard some people say that the cold start helps to keep your CAT in good condition and should only really be turned off if you have a CATless system. Is there any truth to this?
Not really. Cold start off does not heat up the CAT, thus not using the CAT at optimal efficiency, hence why some say there is no point for catted downpipe.
Not ideal but not critical either. Why would you though? What does it give you, if you are consciously not taking advantage of the available power at those higher RPMs? I endeavour to stay below 3000 RPMs, mostly below 2500 until the engine warms up. Too low RPMs are not good either at the beginning.
A lot of people that turn off the cold start say it’s because it revs up to heat up the cats, while that is true that is not the primary reason why it revs up. If revs up because it is cold and needs to run richer than if it is warm, think of it like it’s carbureted, it essentially just has the “choke” on for a bit with slightly raised rpm’s so thag it doesn’t stall from running super rich
I remote start my car (set to 15 minutes) religiously! To allow everything to warm up. I also let the car idle for at least 2-5 minutes when I park it (I use to have a turbo timer) I like to make sure my ECT is showing 170 before I drive off. I have 228k on the clock now. I feel like a "cold start" prolongs the life of the motor along with an oil change every 5k.
@@blacktalonsport1262 it happens because in a cold engine the fuel sets on the cylinder walls. Better to just get in and drive gently. Engineering explained did a video: ruclips.net/video/xKALgXDwou4/видео.html
@@StickyPlasters thanks for the link. I guess my walls are almost gone. Just crossed 229k (I put ALL those miles on it) last night. I've never not used the remote start my car came with. I'll consider not using it on my next motor. Thanks for your comments.
This video is what it looks like when you have to address a question across multiple owners with different vehicles and living situations across the world. Glad it worked for you. Check out what I said at 2:33 let me know what you think
As someone who lives in a really cold area, once it gets below a certain temp cold start gets reactivated. There's a second cold start sequence for the properly cold temps
when it hits around -2 here cold start will run again but not for long, maybe like 10 seconds. on BM3 that is.
That is actually more % on the enrichemnt side. If you start the car in -30* celsius enrichment is somwhere around 180-220% and will sound loud because duh, gasses :)
This is good. For the longest time, with previous cars, I thought starting the car and letting it idle was an ideal way to warm the car and get the oil and coolant to temp... especially during the winter in CT.
My local indy shop, with BMW master techs, have actually told me letting the car idle after a cold start is terrible for fuel injected engines. They have seen issues with idling and adverse effects on the cylinders/cylinder walls that can actually contribute to more engine wear. I've heard this in other places as well. As soon as the car is started and the RPMs fall from the cold start, my wheels are rolling. Biggest thing is, I stay out of the boost and under 3K until the oil gets to temp.
We can’t win can we, running cold hurts the engine and not letting idle hurts it too lol 😂 I’m so paranoid
Letting it idle for several minutes isn’t gonna damage your cylinder walls lol and if the injectors fail they were already bad in the first place, you’ll just have horrible gas mileage by letting it idle
So far so good on mine as well. The one annoying thing was even when the car was warm the car would still do a cold start every time. For example go to get a quick coffee or something after driving for 20min already. It goes in the same cycle. So I disabled it.
Thanks for the video, good as always :).
I am by no means a mechanic but my understanding of cold start is that ECU just opens wastegate 100% and all exhaust is routed directly to downpipe bypassing turbo, that's why it is so annoyingly loud (turbo is no longer muffling the exhaust) and this way catalytic converter is getting warmer faster since all exhaust energy is directed on it without warming up turbo. If at cold start you press on gas pedal a tiny bit, just as much so that ECU feels it, the wastegate gets closed and the car becomes much quieter. I can see wastegate open status on my AK Motion data display. As soon as cold start phase is over (after about 1 min) ECU closes the wastegate. So as I understand the main idea of the cold start is mostly to warm up the catalyst as soon as possible.
My wastegate duty cycle in bootmod shows 99% and when boosting it shows 80-85% what does that mean?
I like the sound of the cold start, my neighbors all have loud cars as well so I never had an issue with wanting to disable.
This is fuckin amazing!! I’m jealous of your neighbourhood 😁
Yeah lucky you, my neighbors always give me a funny look even though my cold start is off now.
My neighbors also have Loud cars and they appreciate the cars around the community
its annoying when it cold starts on every single start up. even when engine is fully warm
@@XandrMotorsports yeah i still get glares after turning off my cold start. might as well as turn it back on
Had cold start off for over 5 years daily driving on b58 and previously n55 and it’s been fine
N55 coldstart is fine. It only cycles when really cold. Not all the time like b58 does.
Did you turn off coldstart with catted downpipe or do you run catless?
@ I have 100 cell sports cat
i don't mind the cold start but wish they'd implemented a system where once the cars up to a certain temp it didn't do the cold start if you start the car again
Some cars actually have that
The manual for the m235i did say that for best fuel economy to drive the car right after starting the car up, and that you dont need to wait for it to "warm up". Like you said, seems like best way to warm up the car is to drive it. Love the videos!
Because when you let a car sit and idle, all you're doing is wasting gas. That's why a lot of states and countries have made it illegal to let your car idle due to the emissions.
@@kern417in germany its even illegal to drive around with ur car for no reason. Just cruising around is against the law.
Let alone letting your engine idle when starting or in summer when u have the AC on in a Parkinglot, people will come up to you knock on the window tell you to turn off your engine.
Much more worse here than in NA.
I live in Canada and I have had the cold start off for over a year now and there has been no issues! on really really cold days the car will disregard the no cold start and cold start, I assume as precautionary reasons. all in all no complaints and I highly recommend
Interesting. So when the temperature is extremely cold and the car has been sitting say all night and you have turned off the cold start via your tune or Carly etc. The car Will cold start as if it wasn’t coded off?
@@anthonyh958 correct, and it’s been coded via bm3
@@anthonyh958 there is a second cold start sequence for when it gets properly cold. It can't be turned off to my knowledge
M240i cold start off for 50k kms stage 2.5 MG flasher in 🇨🇦 . Running perfectly so far, just stay on top of maintenance.
P.s. Kern is the man.
Hey have you noticed difference between stage 2 and 2.5 on pump fuel?
@@QuantomsJune top end a little bit yes, but you have to be WOT to really feel the difference. Otherwise nearly negligible. My next upgrade is a biger turbo that'll perhaps be more noticeable
Do you run catless downpipe?
My b58 heats up pretty quick, and I hate having neighbors close but if I move or it gets real freezing out I might turn it on. Also a side note, not having a cold start and then noticing I had one after a dealer service is the only way I knew they flashed it back to stock and I had to put my stage 2 back on
I’ve had cold start off for about going on 1 years and half . Reason why my cars is way to loud to be cold starting at 5 in the morning. As of right now no problems but I do let the car sit for like 10 mins . I’ve noticed when I’m really really low on gas the idling sometimes sometimes is rough almost as if the car was cammed lol
I turned mine off asap since I leave for work at 5am, live around all old retired people and my exhaust is straight until the muffler 😂
We were just talking about this topic, thank you once again!
I turned mine off and after 4-6 months I felt it have a strange cold start, so turned it back on and everything is fine now
Same. It sounded like a misfire for a few seconds and smelled like fuel out of the exhaust. Now turned back on and starts/ sounds like it should
@@clubsportf56s48 same here, mine shake a bit on start up, and you can see the rpm moving up and down for the first 3 sec
I have cold start off. I drive out of garage everyday at 5am. I let car idle for about 1-2min. This is at the start of the day. If going in and out of a store I will start driving when I’m ready. With my cammed camaro we had cold start off but would
Let idle about 3min at the beginning of the day to allow proper piling on the cam and lifters.
One comment and one question:
- whilst I agree that it is not doing anything for the engine to wait “5 minutes”, the other extreme - cranking and straight on the throttle is definitely not healthy IMO! I ALWAYS wait for the cold start phase to be over before I drive off, since that’s those 20-30 seconds in which I sincerely believe the engine needs to circulate fluids, warm up cylinders and pistons to some minimum operating temp, etc.
As a mechanical engineer, I have yet to see a machine which enjoys being stressed whilst absolutely cold. Note - cold start phase is not equivalent to “putting the engine under load”. Even under load you will never hear the engine make the same noise at 1200 RPM. It is a different procedure.
- How about “Start-up roar”, GTS/Porsche style? I always wonder if that introduces any risks on our engines, when programmed by a tune…
As a mechanical engineer, warming up the engine quickly is key. If you leave the engine to idle, it is spending more run time at lower temperature than it would if you drove the car.
Gts roar is negligible. It only raises the rpm momentarily
@@kern417 I believe you are focusing on one extreme (you keep referring to “5 minutes” or minutes in general), whilst you ignore another - driving off within the first 2 seconds! No machine and no structure appreciates load right away. Cold loading also increases the risk of LSPI, especially for tuned vehicles.
So it is all about balance. My personal formula is ~20-30 seconds which coincidentally is the cold-start, warm-up phase. Plus as you correctly stated - moderate RPMs until the engine gets to somewhat operational temps.
@@kern417 Besides the noise, any downside with the wear on the car (engine) by keeping the cold start OEM and startup roar (flash option in MHD) on a catless setup, while using good judgement until proper oil temp warmup (for me that's about ~10 minutes of babying the RPM/boost)? I suppose the cold start delete can be considered on the catless DP.
Driving out of my driveway is no more rpms then you sitting at cold start. Drive your car.
It's negligible. Nothing to worry about, just run what you prefer.
Have mine turned off for almost 4 years now….zero issues.
how long do you wait before driving?
Hmmm, mines shake a bit on start up and you can see the rpm going up on down for the first 3 seconds of the cold start,
Fantastic,I thought it was just me who was paranoid about turning cold start off!
Thank you for finding out and explaining everything 👍
But now the follow on question Kevin- how the hell does the engine replicate being under load?
Ignition/valve timing
@@kern417 cool, fair enough 🍻
I heard coldstart is important if you have a 8HP ZF Auto Transmission because it heats up that Transmission fluid better so that it doenst jerk from 1st to 2nd hardly when cold.
Anyone can confirm that?
Cold start is awesome. Never turn that off! 🔥🔥
Just turned mine off and was definitely paranoid about it.
Have you kept it off? And what climate do you live in?
Damn, we have -30C here in Canada winter
Quick one. The m140i don’t have temp gages. How do you know when the temps are at a good range?
You can access it in the hidden menu
100% I do the same thing ,just start the car wait a minute and start driving till the engine heats up. Common sense
Is there a benefit with cold start and getting oil quicker through the motor?
Minimal
Quick question for you Kern, when you changed your downpipe did you sell it or kept it?
Sold it
I turned mine off when i went stage 2. I used a 200 cell CAT rather than going completely CAtless. I heard some people say that the cold start helps to keep your CAT in good condition and should only really be turned off if you have a CATless system. Is there any truth to this?
Not really. Cold start off does not heat up the CAT, thus not using the CAT at optimal efficiency, hence why some say there is no point for catted downpipe.
Doesn't make a difference. The cat can handle cold start if you want to leave it on.
Your neighbors will say thank you!
Am I damaging the engine if I do light throttle but shift around 3-3.2k when it hasnt warmed up yet? I use 5w-40 oil
As long as you aren't going into boost which you shouldn't with light throttle you would be fine I shift between 2-3 pretty much all the time
Not the end of the world. Just don't beat on it.
Not ideal but not critical either. Why would you though? What does it give you, if you are consciously not taking advantage of the available power at those higher RPMs?
I endeavour to stay below 3000 RPMs, mostly below 2500 until the engine warms up. Too low RPMs are not good either at the beginning.
A lot of people that turn off the cold start say it’s because it revs up to heat up the cats, while that is true that is not the primary reason why it revs up. If revs up because it is cold and needs to run richer than if it is warm, think of it like it’s carbureted, it essentially just has the “choke” on for a bit with slightly raised rpm’s so thag it doesn’t stall from running super rich
I remote start my car (set to 15 minutes) religiously! To allow everything to warm up. I also let the car idle for at least 2-5 minutes when I park it (I use to have a turbo timer) I like to make sure my ECT is showing 170 before I drive off. I have 228k on the clock now. I feel like a "cold start" prolongs the life of the motor along with an oil change every 5k.
Could be doing more harm than good. You'll be getting cylinder wash
@@StickyPlasters letting it warm up would wash the cylinders? I figured if I didn't let it warm up that could happen.
@@blacktalonsport1262 it happens because in a cold engine the fuel sets on the cylinder walls. Better to just get in and drive gently. Engineering explained did a video: ruclips.net/video/xKALgXDwou4/видео.html
@@StickyPlasters thanks for the link. I guess my walls are almost gone. Just crossed 229k (I put ALL those miles on it) last night. I've never not used the remote start my car came with. I'll consider not using it on my next motor. Thanks for your comments.
I didn’t buy the 340 for the environment the creator of the universe will take care of that , I just want power.
But you have catless
This video is a stretch... I've had my cold start turned off for years with no issues.. granted I'm always garaged in Socal.
This video is what it looks like when you have to address a question across multiple owners with different vehicles and living situations across the world. Glad it worked for you. Check out what I said at 2:33 let me know what you think
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