[ZeroFx]

mines been fine in a 430d. Never seen an issue.

[Jack_is_Back]

I get the comfort hesitation in my 340i - it can be very annoying, dangerous even.

Most noticable when say approaching a roundabout; gently braking, almost to a stop, then quickly off the brake and onto the throttle to make a gap and.... NOTHING!!! I can get my foot all the way to the floor with no reaction, it's that ponderous.

As said, I've learnt to drive around it, usually by flicking the lever into Sport when I anticipate I might need a quick getaway. Picks up almost instantly then.

[Ronstein]

Originally Posted by Jack_is_Back

I get the comfort hesitation in my 340i - it can be very annoying, dangerous even.

Most noticable when say approaching a roundabout; gently braking, almost to a stop, then quickly off the brake and onto the throttle to make a gap and.... NOTHING!!! I can get my foot all the way to the floor with no reaction, it's that ponderous.

As said, I've learnt to drive around it, usually by flicking the lever into Sport when I anticipate I might need a quick getaway. Picks up almost instantly then.

Could it be turbo lag and not the gearbox at all?????

[Watsey]

Originally Posted by Jack_is_Back

I get the comfort hesitation in my 340i - it can be very annoying, dangerous even.

Most noticable when say approaching a roundabout; gently braking, almost to a stop, then quickly off the brake and onto the throttle to make a gap and.... NOTHING!!! I can get my foot all the way to the floor with no reaction, it's that ponderous.

As said, I've learnt to drive around it, usually by flicking the lever into Sport when I anticipate I might need a quick getaway. Picks up almost instantly then.

Exactly this.

The ECUs for the engine and the gearbox are linked - the symptoms strongly indicate an issue in the programming of Comfort mode.

[Watsey]

Originally Posted by Ronstein

Could it be turbo lag and not the gearbox at all?????

It's not turbo lag - the engine revs increase but there's no drive. The modern twin scroll turbos spin up very quickly and in some units, including the 30d, are fed by twin pulses from the exhaust system which helps responsiveness.

[330XDave]

But not for every car....

My 330d is fine, yes I might get the very slightest of hesitations but no more so than is to be expected to be honest, they are machines when all said and done not just computers.

[jinjur]

Originally Posted by 330XDave

But not for every car....

My 330d is fine, yes I might get the very slightest of hesitations but no more so than is to be expected to be honest, they are machines when all said and done not just computers.

325d is twin turbo so I was under the assumption that lag should be even less pronounced.

Today was a good example and more or less what has been mentioned.....approaching a roundabout and then hoping to continue on.......nothing....nothing and then having to press proper resulted in traction control having to step in.

For what is supposed to be an excellent box. ..It's being a bit clumsy

Or I am

[330XDave]

Originally Posted by jinjur

325d is twin turbo so I was under the assumption that lag should be even less pronounced.

Today was a good example and more or less what has been mentioned.....approaching a roundabout and then hoping to continue on.......nothing....nothing and then having to press proper resulted in traction control having to step in.

For what is supposed to be an excellent box. ..It's being a bit clumsy

Or I am

Like has been mentioned it seems some cars are better/worse than others. I've had Audi Multitronic and S tronic boxes and the BMW 8 speed is better than both of them in this situation.

[Techno 9000]

I've accepted that the box in Drive - Comfort or Eco Pro will use the Torque Convertor to smooth the move from stationary quite considerably, this leads to a lag in response to the accelerator pedal.
In Sport-Manual (gear-lever left) in either Comfort or Eco Pro the response is far quicker and I have taken to placing the gear lever left at Roundabouts and other junctions where speed of response is required.
It also has the advantage of waking the engine from its Auto Stop slumber when you see a gap coming.

[speedski]

The normal auto box in the F11 520D was perfectly fine - the sport box in my F36 has this. lull and hesitation and its driving me nuts.

Is there truly a learning process from the box? If so I will ask the dealer to reset it, as I didn't drive the first 12,000 miles on my car....

[SkyJawa]

No need for dealer:

* Press the start button once to turn on power (Don't start the engine)
* Press the accelerator down to the floor, as far as it goes and hold for at least 2 min.
* Do not take your foot off and hit start button once to turn off power
* Remove foot from accelerator
* Wait for another 2 minutes (at least)
* Start the engine and drive

[Soul_Glo]

This was my chief complaint when we bought our 320d. Someone said there was an update. I went to the dealer for new firmware but the problem remained. Gradually I adapted my driving style to anticipate when the throttle would let me down and tried to learn the shift points based on my input. It worked 9/10 times. However, I am pleased to report that with our remap there have been zero issues and this throttle behaviour no longer exists. Might be worth considering a gearbox and throttle map or a full on remap.

I would say it is throttle and not gearbox related as such.

[HighlandPete]

Originally Posted by speedski

The normal auto box in the F11 520D was perfectly fine - the sport box in my F36 has this. lull and hesitation and its driving me nuts.

Is there truly a learning process from the box? If so I will ask the dealer to reset it, as I didn't drive the first 12,000 miles on my car....

I'm running the SAT option in my car, no issues with hesitation, lurching, jolts or lag.

There are misconceptions around the "adapts to driver's style" function. Driver influenced adaptation is a real time function, along with driving environment adaptations. It is not learning a style and holding it in memory, the way many feel it does. How you drive 'currently' is used to adapt the gearbox responses.

Each start up, the gearbox should begin the same way for a given mode. I know mine does, as you drive, driving environment/conditions and driver reactions are feeding in the inputs for how the box will respond. How we use the throttle, brakes, steering, all influence the driver adaptation side of the gearbox function.


Try it... drive gently for a few miles, use slow throttle inputs, you should note how the mph of change points adapt. Drive a few miles in a more purposeful way and change points are moved up the rpm. Back off again and gearchanges drop back down the rpm. An example of my box, at my normal steady pace, 8th will engage around 55mph. Get in a flow of traffic where the pace is reduced, softer accelerations, 8th engagement will drop back to less than 50mph. Drive a bit harder, will be over 60mph, even on similar throttle openings.

What we can get wrong, is erratic inputs, or put the AT into "waiting for instruction" mode. For example, if we suddenly lift off the throttle during acceleration to zero position, gearbox needs the next instruction... are we going to brake, if so it will hold the gear, or are we going to accelerate again? Gearbox upshift suppression causes it to wait until we give it the instruction, either to brake or apply the throttle again. Similar with brake input, is it gentle or a sudden fast application? The function 'brake evaluation' is used, (similar to how the throttle input is monitored), that too can cause the gearbox to take a specific action, or hold, until the next clear input.

Gearbox adaption is another subject altogether. Changes are not made by the driver, any authentic garage reset has a specific teach-in procedure which must be followed, to ensure the whole process is completed.

[HighlandPete]

Originally Posted by SkyJawa

No need for dealer:

* Press the start button once to turn on power (Don't start the engine)
* Press the accelerator down to the floor, as far as it goes and hold for at least 2 min.
* Do not take your foot off and hit start button once to turn off power
* Remove foot from accelerator
* Wait for another 2 minutes (at least)
* Start the engine and drive

You are referring to a throttle reset, nothing to do with driver adaptations for the gearbox.

[Soul_Glo]

Originally Posted by HighlandPete

I'm running the SAT option in my car, no issues with hesitation, lurching, jolts or lag.

There are misconceptions around the "adapts to driver's style" function. Driver influenced adaptation is a real time function, along with driving environment adaptations. It is not learning a style and holding it in memory, the way many feel it does. How you drive 'currently' is used to adapt the gearbox responses.

Each start up, the gearbox should begin the same way for a given mode. I know mine does, as you drive, driving environment/conditions and driver reactions are feeding in the inputs for how the box will respond. How we use the throttle, brakes, steering, all influence the driver adaptation side of the gearbox function.


Try it... drive gently for a few miles, use slow throttle inputs, you should note how the mph of change points adapt. Drive a few miles in a more purposeful way and change points are moved up the rpm. Back off again and gearchanges drop back down the rpm. An example of my box, at my normal steady pace, 8th will engage around 55mph. Get in a flow of traffic where the pace is reduced, softer accelerations, 8th engagement will drop back to less than 50mph. Drive a bit harder, will be over 60mph, even on similar throttle openings.

What we can get wrong, is erratic inputs, or put the AT into "waiting for instruction" mode. For example, if we suddenly lift off the throttle during acceleration to zero position, gearbox needs the next instruction... are we going to brake, if so it will hold the gear, or are we going to accelerate again? Gearbox upshift suppression causes it to wait until we give it the instruction, either to brake or apply the throttle again. Similar with brake input, is it gentle or a sudden fast application? The function 'brake evaluation' is used, (similar to how the throttle input is monitored), that too can cause the gearbox to take a specific action, or hold, until the next clear input.

Gearbox adaption is another subject altogether. Changes are not made by the driver, any authentic garage reset has a specific teach-in procedure which must be followed, to ensure the whole process is completed.

[SkyJawa]

Originally Posted by HighlandPete

You are referring to a throttle reset, nothing to do with driver adaptations for the gearbox.

Very true but thought it was worth posting again as a few people have said in the past it’s helped them with this issue....

[Manivxr]

Originally Posted by SkyJawa

Very true but thought it was worth posting again as a few people have said in the past it’s helped them with this issue....

Plus it shares knowledge to a wider group.
Thanks SkyJawa I have learnt something new today.
Great thing this forum.

[NanasBack]

My 335d does it.
I drive 99% of the time in comfort mode so haven't noticed if other modes are different.
If you are slowing at a junction and 'see a gap' it can catch you out because of the delay.
If you actually stop and need to get off smartish, I move my left foot onto the brake and tap the throttle slightly with my right.
That seems to sort the gears/ clutches out.
Hitting the throttle then is like launch. 😀

[speedski]

I tried the throttle reset today and I honestly feel it made a difference, I was only running to the airport so didnt have much time to try it out fully as its mostly motorways but ill take the long road home when I get back in a few days and see if it really has made a difference.

Thanks for the tip, appreciated!

[Jeff123]

In comfort mode you start off in 2nd gear. Maybe some people are expecting too much from a standing start. As mentioned before, if it’s an issue try it in sport mode for a while and see how it goes then.

[Techno 9000]

I didn't realise that was the case, but makes sense as to why the torque converter would be smoothing the take off from stationary so much in Comfort - Drive.
Also explains the clear difference when in Comfort - Sport / Manual (as I presume it does start off in first gear).

[speedski]

In my case its not what gear you set off in, its the travel on the throttle before anything happens that I think was causing my issue - I could move the pedal gently and it took a while to kick in.

Its was especially prevalent on reverse up a slight incline, and I do mean slight - thats the thing I need to test next, that will tell me if the reset has had any impact at all.