Engine turns itself back on?

Crowden · 08-29-2016, 07:53 PM

I'm wondering if others have had the issue of the car's engine deciding on its own that it's time to turn on. Foot on the brake, no variation I'm aware of in pedal pressure, yet the car will sometimes stay off and sometimes just decide "eh, I'm bored being off, time to start up again". Was going to mention it when I bring it in for the first service in a couple months but curious if it's a widespread thing.

orangeglim · 08-29-2016, 08:03 PM

When does this happen? At a stop light, with auto start/stop enabled?

Crowden · 08-29-2016, 08:12 PM

Quote:

Originally Posted by orangeglim

When does this happen? At a stop light, with auto start/stop enabled?

Correct.

MrBucket · 08-29-2016, 08:14 PM

It's decided the battery is getting low enough that it needs to start charging it up again by running the alternator.

Questofthetune · 08-29-2016, 08:19 PM

Also the climate control will kick it on too

BMWZ4 · 08-29-2016, 08:21 PM

Wait...start/stop button is enabled? Isn't it doing exactly what it's supposed to do? Turn off, then back on again?

Unless I'm missing something....

xantdieselx · 08-29-2016, 08:33 PM

Normal operation. Once the battery reaches below a certain level with ASS enabled the car will start back on its own.

MrBucket · 08-29-2016, 08:33 PM

Quote:

Originally Posted by Questofthetune

Also the climate control will kick it on too

Yes, because running it off the battery drains it quickly.

Crowden · 08-29-2016, 08:38 PM

Quote:

Originally Posted by BMWZ4

Wait...start/stop button is enabled? Isn't it doing exactly what it's supposed to do? Turn off, then back on again?

Unless I'm missing something....

Yep, missing something. It's supposed to turn back on when I take my foot off the brake, not while the car is at a standstill waiting for the light to change. ;-)

Crowden · 08-29-2016, 08:39 PM

Quote:

Originally Posted by MrBucket

Yes, because running it off the battery drains it quickly.

Gotta admit I'm surprised it would start up that quickly. We're talking 20 or 30 seconds before starting back up at times.

redontheline · 08-29-2016, 08:39 PM

Everyone has given the answer. It's constantly monitoring the battery status. That's why sometimes you'll notice it won't turn off at all at a light.

Questofthetune · 08-29-2016, 09:08 PM

Quote:

Originally Posted by MrBucket

Yes, because running it off the battery drains it quickly.

Not sure how I didn't put 2+2 together lol

DanG · 08-29-2016, 09:11 PM

And when it is hot outside and AC running it will turn itself back on after only a few seconds.

Elvisfan · 08-29-2016, 09:12 PM

Read the manual. The engine will start if it's not warmed up. If the battery is low. If it's too hot to maintain the cabin temp. There are many reasons the car will start.
Page 70

SchmullisBob · 08-30-2016, 07:15 AM

Solution - Never use start / stop !

bozman9 · 08-30-2016, 09:48 AM

All are correct and this is similar to any car I have owned with stop/start. Depending on engine temp, battery charge, A/C use, external temp, all sorts of things, the engine will turn back on. If the car is warmed up, nice day out, no A/C on, no seat warmers on (they pull current too), etc you will find that it stays off longer (but not forever).

The 2'er start/stop system is actually one of the least intrusive I have seen/used, in terms of "jolting" the car or stutter stop/start/stop activity. Also note - it deactivates in sport mode.

Bozman

raleedy · 08-30-2016, 10:50 AM

RTFM, as suggested. In addition to the conditions mentioned above, it will restart the engine if you crank the steering wheel or, in the automatic, move the shift lever over to "S". Here's a fun fact for 6MT owners: if you are careless with the clutch (for example, mistakenly trying to start out in third instead of first) and kill the engine (there is just zero torque at idle in this car), AutoStartStop will restart it for you as if nothing happened when you push the clutch back in.

MrBucket · 08-30-2016, 06:30 PM

Quote:

Originally Posted by bozman9

All are correct and this is similar to any car I have owned with stop/start. Depending on engine temp, battery charge, A/C use, external temp, all sorts of things, the engine will turn back on. If the car is warmed up, nice day out, no A/C on, no seat warmers on (they pull current too), etc you will find that it stays off longer (but not forever).

The 2'er start/stop system is actually one of the least intrusive I have seen/used, in terms of "jolting" the car or stutter stop/start/stop activity. Also note - it deactivates in sport mode.

Bozman

You can have it in sport mode, but not sport+ at all.

BillD1953 · 09-02-2016, 09:48 AM

Quote:

Originally Posted by SchmullisBob

Solution - Never use start / stop !

Agreed.....the doggone stopping/starting at lights is way too annoying....and how much fuel do you "really save" in the mode ????

redontheline · 09-02-2016, 10:37 AM

Quote:

Originally Posted by BillD1953

Agreed.....the doggone stopping/starting at lights is way too annoying....and how much fuel do you "really save" in the mode ????

I actually really love it and have full control with the MT. Coming to a light that's about to change or a lonely road stop sign? Just keep the clutch in.

BentZero · 09-02-2016, 10:05 PM

I disabled that mess a long time ago.

raleedy · 09-03-2016, 11:13 AM

Hard to grasp why anyone would want the engine running when it isn't needed.

08-29-2016, 07:53 PM	#1
Crowden Private 39 Rep 57 Posts Drives: 2016 M235i Join Date: Apr 2015 Location: Bay Area, California iTrader: (0)	Engine turns itself back on? I'm wondering if others have had the issue of the car's engine deciding on its own that it's time to turn on. Foot on the brake, no variation I'm aware of in pedal pressure, yet the car will sometimes stay off and sometimes just decide "eh, I'm bored being off, time to start up again". Was going to mention it when I bring it in for the first service in a couple months but curious if it's a widespread thing. __________________ Current ride: BMW M235i. Estoril/Terra, 8 spd, tech, tech and more tech. Past rides: GTI Mk1, Volvo 850T, VW Passat 6 spd, BMW Z3 2.3, BMW Z3 3.0, BMW E36, BMW E46, BMW E90, BMW E90, BMW Z4 3.0is, GTI Mk6, GTI Mk6, GTI Mk7.
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08-29-2016, 08:03 PM	#2
orangeglim Lieutenant 345 Rep 442 Posts Drives: 2019 M2C Join Date: May 2016 Location: NC iTrader: (0) Garage List 2019 M2C [0.00]	When does this happen? At a stop light, with auto start/stop enabled?
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08-29-2016, 08:14 PM	#4
MrBucket Captain 257 Rep 721 Posts Drives: '17 AW M2 6MT Exec Pack Join Date: Aug 2014 Location: United States iTrader: (0)	It's decided the battery is getting low enough that it needs to start charging it up again by running the alternator.
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08-29-2016, 08:19 PM	#5
Questofthetune Captain 446 Rep 780 Posts Drives: 13 GT50014 AW M235i(sold) Join Date: Jul 2016 Location: SFL iTrader: (1) Garage List 2014 BMW 235i [0.00]	Also the climate control will kick it on too
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08-29-2016, 08:21 PM	#6
BMWZ4 Major General 1910 Rep 5,105 Posts Drives: '23 X1/'23 Allroad Progressiv Join Date: Apr 2010 Location: Toronto iTrader: (1)	Wait...start/stop button is enabled? Isn't it doing exactly what it's supposed to do? Turn off, then back on again? Unless I'm missing something.... __________________ '11 Z4 30i (retired);'11 X3 28i (retired); '15 M235i Stage 1 Dinan (recalled & crushed); '16 M235i Stage 3 Dinan (retired); '15 X3 28i (retired); '14 328i (retired), 2019 X3M40i (retired); Loaded '18 X1 (retired); Loaded '20 X3MC DG, Black/Tan Merino (retired); Loaded '23 X1 Cape York green and Red/Black interior; '23 Audi A4 Allroad Progressiv
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08-29-2016, 08:33 PM	#7
xantdieselx Kingslayer 411 Rep 1,479 Posts Drives: 23' M3 Base Join Date: Jun 2008 Location: SWFL iTrader: (0)	Normal operation. Once the battery reaches below a certain level with ASS enabled the car will start back on its own. __________________ Previous Cars: 2008' 135i, 2010' 328i, 2013' 328i, 2016' M235i, 2017' X1, 2019' M240i Current Cars: 2019' X3, 2021' M3 Comp
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08-29-2016, 08:39 PM	#11
redontheline Second Lieutenant 71 Rep 222 Posts Drives: EB 235 MT Join Date: Jan 2016 Location: NJ iTrader: (0)	Everyone has given the answer. It's constantly monitoring the battery status. That's why sometimes you'll notice it won't turn off at all at a light.
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08-29-2016, 09:11 PM	#13
DanG Major General 10662 Rep 6,938 Posts Drives: 2018 M2 AW DCT Join Date: Aug 2012 Location: Seattle, WA iTrader: (1) Garage List 2018 BMW M2 [7.68]	And when it is hot outside and AC running it will turn itself back on after only a few seconds.
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08-29-2016, 09:12 PM	#14
Elvisfan Major 516 Rep 1,452 Posts Drives: 2018 430ix convertible MGM Join Date: Jun 2016 Location: Illinois iTrader: (0)	Read the manual. The engine will start if it's not warmed up. If the battery is low. If it's too hot to maintain the cabin temp. There are many reasons the car will start. Page 70 Last edited by Elvisfan; 08-29-2016 at 09:18 PM.. Reason: Page in manual
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08-30-2016, 07:15 AM	#15
SchmullisBob Private 40 Rep 61 Posts Drives: M235i Coupe - 2015 Join Date: Apr 2016 Location: Gainesville, FL iTrader: (0)	Solution - Never use start / stop !
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08-30-2016, 09:48 AM	#16
bozman9 Private 15 Rep 72 Posts Drives: 2016 M235xi CV Join Date: May 2016 Location: Worcester, MA iTrader: (0)	All are correct and this is similar to any car I have owned with stop/start. Depending on engine temp, battery charge, A/C use, external temp, all sorts of things, the engine will turn back on. If the car is warmed up, nice day out, no A/C on, no seat warmers on (they pull current too), etc you will find that it stays off longer (but not forever). The 2'er start/stop system is actually one of the least intrusive I have seen/used, in terms of "jolting" the car or stutter stop/start/stop activity. Also note - it deactivates in sport mode. Bozman
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08-30-2016, 10:50 AM	#17
raleedy Colonel 160 Rep 2,248 Posts Drives: 2016 228i 6-speed Join Date: Jul 2005 Location: Portland, Oregon iTrader: (0)	RTFM, as suggested. In addition to the conditions mentioned above, it will restart the engine if you crank the steering wheel or, in the automatic, move the shift lever over to "S". Here's a fun fact for 6MT owners: if you are careless with the clutch (for example, mistakenly trying to start out in third instead of first) and kill the engine (there is just zero torque at idle in this car), AutoStartStop will restart it for you as if nothing happened when you push the clutch back in.
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09-02-2016, 10:05 PM	#21
BentZero Lieutenant Colonel 625 Rep 1,753 Posts Drives: 6MT Mineral White M235i Join Date: Oct 2015 Location: Charleston, SC iTrader: (2)	I disabled that mess a long time ago. __________________ I rev-match from neutral to first 6MT Mineral White on black M235i coupe Build thread
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09-03-2016, 11:13 AM	#22
raleedy Colonel 160 Rep 2,248 Posts Drives: 2016 228i 6-speed Join Date: Jul 2005 Location: Portland, Oregon iTrader: (0)	Hard to grasp why anyone would want the engine running when it isn't needed.
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