[geye1970]

I usually have start stop disabled, unless I happen to know I'll be stuck at a long light , in which case I enable it as I approach the light.

This has always worked for me and the engine would turn off.

Recently (last week) it has decided that it does not want to work 4/5 times. This is with the climate off and engine warm. This is a 2015 x3 2.0 I4 engine.

Any thoughts?

[alpineweissF25]

Are you on the original battery? Do you drive short miles each trip?

The start stop system takes into account battery voltage and demand on the electrical system and if needs be will prevent the engine from stopping.

Might be worth testing your battery to see what voltage it's holding.

[TheCoolX3]

Unlikely that the battery is bad but your issue is most likely that it is low on juice.

Take it for a long drive or invest in a battery charger!

[geye1970]

Originally Posted by alpineweissF25

Are you on the original battery? Do you drive short miles each trip?

The start stop system takes into account battery voltage and demand on the electrical system and if needs be will prevent the engine from stopping.

Might be worth testing your battery to see what voltage it's holding.

Is there a way to check the voltage via the secret menu? Can I access the secret menu via the IC on the F25 ?

Originally Posted by TheCoolX3

Unlikely that the battery is bad but your issue is most likely that it is low on juice.

Take it for a long drive or invest in a battery charger!

I actually just took it on one of the longer drives in a while this past weekend - 100 miles round trip.

[Kiemyster]

Originally Posted by geye1970

Is there a way to check the voltage via the secret menu? Can I access the secret menu via the IC on the F25 ?


I actually just took it on one of the longer drives in a while this past weekend - 100 miles round trip.

Not sure if you can get a voltage readout on the dash. The battery chargers usually have a charge indicator on it, but you will need to do a slow charge. most battery chargers have several charging levels, best way to restore battery health is to connect and charge at lowest level, once it reads 100%, disconnect for a few minutes and re-charge. Do that for 2-3 days and your battery will be in as good shape as it can be in. I have six bimmers and don't have time to drive them all consecutively, so I am always dealing with low battery charges.

[oVeRdOsE.]

anyway, no matter how BMW will say it, having the engine OFF get you into no oil pressure at all, so the rod bearing are touching the cranck shaft.
Engine on, the oil pressure will make a small oil film all around the rod bearing so metal wont touch metal. Wear is worst with time, since oil loose initial specs.

Same principle with cam lobe, hpfp and so on. start-n'-stop will make slight metal-metal friction.

Yes its been proven that you will save fuel, but whats worst for the environment getting a new or rebuilt engine because its worn out @ 180k miles?

knowing bmw are not the best with their rod bearing, I,ve disable this function. Planning to keep the car 10+ years.

[malicem3]

Originally Posted by oVeRdOsE.

anyway, no matter how BMW will say it, having the engine OFF get you into no oil pressure at all, so the rod bearing are touching the cranck shaft.
Engine on, the oil pressure will make a small oil film all around the rod bearing so metal wont touch metal. Wear is worst with time, since oil loose initial specs.

Same principle with cam lobe, hpfp and so on. start-n'-stop will make slight metal-metal friction.

Yes its been proven that you will save fuel, but whats worst for the environment getting a new or rebuilt engine because its worn out @ 180k miles?

knowing bmw are not the best with their rod bearing, I,ve disable this function. Planning to keep the car 10+ years.

Agreed. I believe the eccentric shaft failure correlates to Auto Start/Stop functionality.