[F90CP]

Hi,

I have noticed when I turn the car on, the engine turns for around 5 seconds a few times before firing up, it almost sounds as if its struggling.. anyone had this issue before, any idea's?

Also when the stop start button is activated and the car auto stops when i am at stand still, when i continue it fires up and jerks forward very harshly, I have to hit the brake hard to stop it moving, it used to obviously just turn on and wait for me to move.. again any idea what this is??

a few times its come up with a draintrain error and says i cannot continue to drive, i then have to restart the car and its normal again.

[DannyA]

Yeah defo not normal. These things have a Lithium battery and should crank instantly.

With mine, if I am in traffic and the start stop kicks in it doesnt move, I am guessing you don't use the auto h?

[F90CP]

no i dont use auto H, i might try that though and see what happens.. the crank is worrying tho it takes a few attempts then fires up

[Burnsey]

If the car is in use, with start/stop activated or not, you should still have your foot on the brake, or the handbrake engaged.

What do you expect to happen, with a car in drive when it starts?

The crank - do you have a tracker installed? My car sometimes hasn't 'found' the fob, so takes a couple of attempts.

[F90CP]

I get what your saying, just previously when I 1st had the car and even my range rover with auto start, naturally when you get to lights or s something the car will turn off but as soon as you let go of the brake it turns on and you can carry on, the thing now is that when it auto starts it jerks really aggressively when it turns on, it didnt do that before.. also sometimes comes up with a drive train error and says you cannot drive but a restart fixes it. Tracker is on the car but not activated at the moment, never been an issue before just randomly started behaving this way..

[JOHNBMWM5]

Originally Posted by F90CP

I get what your saying, just previously when I 1st had the car and even my range rover with auto start, naturally when you get to lights or s something the car will turn off but as soon as you let go of the brake it turns on and you can carry on, the thing now is that when it auto starts it jerks really aggressively when it turns on, it didnt do that before.. also sometimes comes up with a drive train error and says you cannot drive but a restart fixes it. Tracker is on the car but not activated at the moment, never been an issue before just randomly started behaving this way..

Yea that's NOT normal at all, with or without Stop start engaged, could be fuel pump/air in the lines , or software, get it checked ASAP.
Battery check needed also.

[Burnsey]

Originally Posted by JOHNBMWM5

Yea that's NOT normal at all, with or without Stop start engaged, could be fuel pump/air in the lines , or software, get it checked ASAP.
Battery check needed also.

Yep, certainly has something not quite right.

[A Need For Speed]

Originally Posted by F90CP

Hi,

I have noticed when I turn the car on, the engine turns for around 5 seconds a few times before firing up, it almost sounds as if its struggling.. anyone had this issue before, any idea's?

Also when the stop start button is activated and the car auto stops when i am at stand still, when i continue it fires up and jerks forward very harshly, I have to hit the brake hard to stop it moving, it used to obviously just turn on and wait for me to move.. again any idea what this is??

a few times its come up with a draintrain error and says i cannot continue to drive, i then have to restart the car and its normal again.

I can't imagine the auto start/stop would save enough fuel to be worth the hassle? Why do you use it? Just curious, not being critical.

As to the car dying on startup, that is happening to a bunch of us about once a week. There are numerous threads on this. Likely a fuel pump issue but in my instance, if you can't reproduce in front of dealer, it is no issue in their eyes. I have started video recording startups...I hope others do this as well and we can post and copy videos to show this problem to our dealers and get this resolved.

You mention a drivetrain error warning...I am not getting that....that can be anything from fouled plug to serious issue so I would get that checked out.

Good luck.

[F90CP]

I dont use the start stop, its only when I forgot to turn it off that i realize after it does the stupid jerk, its like when it fires up its in gear which is normal but instead of being stationary because hte brake is pressed it jerks forward and because the brake it pressed it comes up with the error drivetrain, if the brake is not pressed it will just fire up almost as when u fire up with sport plus, but instead of just make the loud noise it actually goes forward a bit as well..

Slow startup happens in the cold more, i noticed this morning happened but last night after i had been driving when i returned it on it didnt take too long was almost normal..

I have a video let me post it

[F90CP]

player.vimeo.com/video/396878347

[Higgs Boson]

Direct Injection engines have longer crank times programmed in when it's colder to properly build high fuel pressure in the rails. Normal to have a slightly extended crank time when it's cold. You live in London, I live in Texas, I don't have that issue.

Engine dying at startup "can" be caused by quick pressing the Start/Stop button instead of holding it. Some brands you can tap it and it will crank long enough to fire up and run, some brands you have to hold it for a second or two to make sure it starts up right. Try holding the button down just a second longer and see if you still have the issue.

Auto Start/Stop saves a manufacturer about 30% on their CAFE mpg and it's reasonable to believe that under the right driving conditions (city driving, not highway obviously) it can save individual cars a similar amount, trucks and large vehicles on the high side. BMW has the worst implementation of Start/Stop I have encountered so far. You have to press firmly on the brake, even a slight pressure release of the pedal can cause the engine to start but still retain a brake signal, possible causing the error message and abrupt restart situation since you are still applying some resistance to forward motion. Try holding the brakes only slightly more firmly and not releasing any pressure until you are ready to go for sure or use your Auto Hold function so you don't have to do anything.

If you don't mind, let us know if any of this works for you so we can either do these things or rule them out.

[F90CP]

Thanks for this, I will try it and let you know.. I know though that no matter what I do when it auto starts it starts with a boom and launches forward so I have to press the brake or just remember to press the auto start to OFF and manually start it.. none of this used to happen it randomly started so its worrying me.. I get the cold start bit so I agree maybe thats just normal due to cold weather..

Originally Posted by Higgs Boson

Direct Injection engines have longer crank times programmed in when it's colder to properly build high fuel pressure in the rails. Normal to have a slightly extended crank time when it's cold. You live in London, I live in Texas, I don't have that issue.

Engine dying at startup "can" be caused by quick pressing the Start/Stop button instead of holding it. Some brands you can tap it and it will crank long enough to fire up and run, some brands you have to hold it for a second or two to make sure it starts up right. Try holding the button down just a second longer and see if you still have the issue.

Auto Start/Stop saves a manufacturer about 30% on their CAFE mpg and it's reasonable to believe that under the right driving conditions (city driving, not highway obviously) it can save individual cars a similar amount, trucks and large vehicles on the high side. BMW has the worst implementation of Start/Stop I have encountered so far. You have to press firmly on the brake, even a slight pressure release of the pedal can cause the engine to start but still retain a brake signal, possible causing the error message and abrupt restart situation since you are still applying some resistance to forward motion. Try holding the brakes only slightly more firmly and not releasing any pressure until you are ready to go for sure or use your Auto Hold function so you don't have to do anything.

If you don't mind, let us know if any of this works for you so we can either do these things or rule them out.

[M5stu]

Your cold start issue in the video is definitely doesn't look right to me even in colder temps and would suggest taking in using the video as evidence to get BMW service to investigate.

The stop start issue as mentioned by others doesn't sound right either. Probably worth a video of that too if you want others to compare experience.

Hope you get it all sorted and be good to hear how you get on.