5 months, I still have no clue how my auto start, stop works

[f32458]

sometimes it just shuts off for 30 seconds, then sometimes it doesn't. It even shuts off during cold start from morning. It is very annoying and sometimes I just forgot the press the button.

[F82_SID]

Originally Posted by f32458

sometimes it just shuts off for 30 seconds, then sometimes it doesn't. It even shuts off during cold start from morning. It is very annoying and sometimes I just forgot the press the button.

I cant figure it out either. I try and show people how it works and I come to a stop and then the engine doesnt shut off and I look like a dumb ass lol. I am just glad that it is turned off by default in the 2011.5s!

[Stronghammer]

I know just pressing the button is insufficient. Time to open the manual.

[Chowster]

Uh... read the manual. It only shuts off when the engine is at the proper operating temp. Also, the cabin temp also has to reach the set temp. If the engine shuts off and the cabin temp changes, the engine turns back on by itself even if your foot remains on the brake.

[swartzentruber]

Originally Posted by Chowster

Uh... read the manual. It only shuts off when the engine is at the proper operating temp. Also, the cabin temp also has to reach the set temp. If the engine shuts off and the cabin temp changes, the engine turns back on by itself even if your foot remains on the brake.

These are all correct, although the "proper operating temp" doesn't seem to be that high. I've had stop-start activation after ~5 minutes of driving in warmer temps, with the oil temp gauge well below center. The biggest "trick" around activation is that you need to brake pretty firmly, and can't let the pressure up much. If you don't brake firmly, I think it registers as being in stop-n-go traffic, and it doesn't shut off in those instances. I've found it's a bit tough to brake smoothly in my normal manner, and still get it to engage (definitely better if you don't have passengers).

If the car restarts and you weren't expecting it, in my experience usually it's either due to A/C needing to run (car heating up), or pressure on the brake was released. I'll admit the system is still a little tricky to engage consistently -- I think I work at it because the tech geek in me finds the system fascinating, even if it doesn't always work how I think it should.

[HeartMD]

I have not yet to this day totally understood the rationale behind this function. I think its basically a gimic. There is no way that constantly turning the engine on and off could be good for it. Also I personally would find it a major annoyance if this were to happen admist stop and go traffic, which would make the savings in gas completely negligable.

[aus]

Originally Posted by HeartMD

I have not yet to this day totally understood the rationale behind this function. I think its basically a gimic. There is no way that constantly turning the engine on and off could be good for it. Also I personally would find it a major annoyance if this were to happen admist stop and go traffic, which would make the savings in gas completely negligable.

You're right, but it if allows BMW to get a lower (or even avoid) the gas guzzler tax, I'm all for it. It's not like it's on by default. That would be a problem.

[dapopa9]

Do the 2008's have this feature? If so how do I turn it on/off?

[Bosna]

2008's do not have this feature. I believe 2011 is the first year with it.

[Tomislav]

Thank god 08's didn't have it, it just sounds like an annoying feature

[swartzentruber]

I'm always surprised by how much criticism this feature gets. First, it's off by default (at least in the US), so how could it be annoying -- if you don't want to use it, nobody is trying to make you to. Second, it's definitely not a gimic -- it definitely can save quite a bit of gas, depending on the commute; others not so much, but that's the same with any gas saving features. As far as it being hard on the engine or batteries, batteries have made great strides in the last few years, plus BMW I believe uses a slightly more durable starter in cars with this feature. Frankly, I'd rather have increased wear on batteries/starter, than the wear on the engine from the car just sitting and idling at a light.

The system will not normally shut off in stop-n-go traffic. As I mentioned earlier, you have to brake firmly and keep your foot on the brake, so if you brake lightly and then release, it won't activate. It seems like it works best in commutes similar to mine, where you are either driving, or waiting at fairly long stop lights. I don't have enough history for a completely reliable estimate, but I think on my commute, it's probably saving around 25%.

[goldminer]

Originally Posted by swartzentruber

These are all correct, although the "proper operating temp" doesn't seem to be that high. I've had stop-start activation after ~5 minutes of driving in warmer temps, with the oil temp gauge well below center. The biggest "trick" around activation is that you need to brake pretty firmly, and can't let the pressure up much. If you don't brake firmly, I think it registers as being in stop-n-go traffic, and it doesn't shut off in those instances. I've found it's a bit tough to brake smoothly in my normal manner, and still get it to engage (definitely better if you don't have passengers).

If the car restarts and you weren't expecting it, in my experience usually it's either due to A/C needing to run (car heating up), or pressure on the brake was released. I'll admit the system is still a little tricky to engage consistently -- I think I work at it because the tech geek in me finds the system fascinating, even if it doesn't always work how I think it should.

Do you have DCT? I have the 6MT and it is not even necessary to apply the brakes for the autostart feature to work. You simply depress the clutch, shift into neutral and let the clutch back out. It restarts when you depress the clutch again. I believe the car needs to be fully stopped as well but am not certain. I've never tried to roll up to a stop in neutral to see if it will shut off. I wouldn't want to. Might loose power steering and there is no drive if you need it??

I was confused by it at first as well because it often didn't shut down. This turned out to be most likely due to air the conditioning being on. The car has a number of conditions which must be met before it will shut down, many of which have been outlined above. Now that we are driving in warm fall weather and the electrical loads are light it almost always shuts off. In summer it is at best a 50:50 bet as to whether it will.

[Jacque8883]

I have a 2010 E92 and default is ON. Anyone knows how to make it default to OFF?

[SamS]

Originally Posted by Jacque8883

I have a 2010 E92 and default is ON. Anyone knows how to make it default to OFF?

In the US, the default is Off. But you would have to get your car custom-coded to change the default. Your dealer likely won't do it, and it's not a setting you can change.

[BMW Fanatic]

Originally Posted by Jacque8883

I have a 2010 E92 and default is ON. Anyone knows how to make it default to OFF?

By ON do you mean the light is ON or OFF

[///My5UV]

It's kinda nifty, and there's a coding option to make it remember the last setting, so you get the best of both worlds... on if you like it, off if you don't, and you can choose which. (This is really the way they should have shipped it in the first place!)

My only annoyance is that sometimes when it starts back up the cigarette lighter loses power for an instant so the radar detector resets. I assume I can hardwire to a more constant voltage source but it hasn't been that big of a deal yet.

I'm also annoyed that I didn't get a break on the gas guzzler tax with it.

[swartzentruber]

Originally Posted by goldminer

Do you have DCT? I have the 6MT and it is not even necessary to apply the brakes for the autostart feature to work. You simply depress the clutch, shift into neutral and let the clutch back out.

Yeah, I'm describing for a DCT (driven 6MT most of my life until this car, how soon I forget). I'm pretty sure you must be at a complete stop. I have to brake firmly (to a stop) for it to activate.

[BayBayBay]

I believe in addition to having engine in correct operating temp, your steering also needs to be centered. If it is not centered and the car detects it will not activate. If you are in a turn and brake to a stop, the engine will not stop.

[bobbyd1961]

sounds stupid