Hesitation issues.

[Maddog]

show it some assurance in what you do

Is that the same as

give it a good flogging and tell it who's boss

Agreed, it works!

[y5choi]

if you read some of the literature on the E70 xdrive, you will find out that the all wheel drive system is a "proactive" system that calculates traction and accelerator movement to best apply the tourque and power before the car starts to move- Flexray can make it happen in 0.1 seconds (100 ms). If you find that when you depress the gas pedal suddenly and the car hesitates for about 0.1 sec, you know its the xdrive working properly for you so you don't get the mad back end sliding.

If the hesitation is longer than that, i'd an engine issue.

When I first started to drive my 4.8i it did experience the hesitation. I'd press on gas, wouldn't move, so i'd give it more, then just BOOM! shoots forward, then I panic and pull my foot off the pedal, and the car jerks and everything inside it ... then other people wonder if I've gone mad

[Muz]

I have my doubts.. I ve tried lots of techniques but IMO this transmission is one of the worst I 've come across and its my second X5 .. can I Have my old 4.6 back please

[morecowbell]

Originally Posted by y5choi

When I first started to drive my 4.8i it did experience the hesitation. I'd press on gas, wouldn't move, so i'd give it more, then just BOOM! shoots forward, then I panic and pull my foot off the pedal, and the car jerks and everything inside it ... then other people wonder if I've gone mad

Serious question...when you say "not moving...is the car literally "not moving" or just not "peppy"???

[rh71]

from the thread I posted, a BMW technician quoted:

Adaptive Hydraulic Pressure Control
Pressure adaptation has been a feature of ZF automatic transmissions since the 4HP22EH.
The TCM will maximize shift quality by adapting to transmission wear over time. The TCM
will adjust transmission shift pressures to compensate for wear in the multi-plate clutches.
This is accomplished by monitoring the input and output speeds of the transmission. When
the transmission shifts, the TCM monitors the time that it takes to accomplish the shift. The
time change in gear ratio is monitored and compared to an internal time value in the TCM.
If the ratio change takes more time than the stored value, the TCM will compensate by
adjusting the transmission shift pressures via the EDS valve solenoids. The adaptation
value is stored in the TCM. This adaptation values can only be cleared by the diagnostic
tester (DIS plus or GT-1).

Note: DO NOT clear adaptation values unless directed to do so by technical assistance.
Clearing pressure adaptations should not be done to resolve a customer
complaint. The only time that you would need to do so is after a transmission or
valve body replacement or software change.

Also it is important not to confuse pressure adaptation with AGS features. AGS
features will be discussed later in this chapter. AGS features are not stored on a
long term basis and will not be cleared when the pressure adaptations are
cleared. Note: Driving style is NOT stored.

Adaptive Features (AGS)
AGS features were introduced in 1994 with the A5S560Z transmission. AGS control consists
of adaptive features that will modify transmission operation according to various factors.
AGS operation can be influenced by two major functional groups:
• Driver influenced features (influenced by throttle and kickdown input)
• Environmental influences (such as road conditions - icy, traffic etc.)
The driving program selection is not adapted on a long term basis - nor is it stored
in the control module memory when the ignition is switched off. It continually
changes as the driver of the vehicle changes driving habits.

It learns but only during the drive... it is not stored in memory once the vehicle is turned off. 4 different techs contributed to that thread.

[AzNMpower32]

Originally Posted by y5choi

if you read some of the literature on the E70 xdrive, you will find out that the all wheel drive system is a "proactive" system that calculates traction and accelerator movement to best apply the tourque and power before the car starts to move- Flexray can make it happen in 0.1 seconds (100 ms). If you find that when you depress the gas pedal suddenly and the car hesitates for about 0.1 sec, you know its the xdrive working properly for you so you don't get the mad back end sliding.

No, it can't be the xDrive system. Folks with E53s and pre-facelift X3s have no hesitation problems at all with their cars.

Not to get overly technical, but here's some pointers on xDrive:

1. When starting off, the differential is fully locked to optimise traction.

2. When doing parking maneuvers (large steering angles below 20km/h), the xDrive is decoupled to be rear-wheel drive to reduce driveline forces when parking.

3. After starting off as the vehicle gains speed over 20km/h, the xDrive splits the torque 40/60 default, unless other factors warrant a change in distribution

There isn't a "magical" redistribution of power when you accelerate, and hence, there isn't any reason for xDrive to cause any hesistation or delay. And like I said, it works perfectly fine in my X3 or any of the older BMWs.

It's the gearbox. BMW hasn't bothered to iron out the 6AT issues on the 328xi, 2007+ X3, or X5 for some reason.

[y5choi]

Originally Posted by morecowbell

Serious question...when you say "not moving...is the car literally "not moving" or just not "peppy"???

yes, it won't move. well, doesn't happen now that I'm more used to the car but yea i'd push on and it won't move (engine revs, but car doesn't move) for a split second- notice it if i want to really quickly turn-in to a street or likewise.

Hmm.., Yeah i've been thinking it's the Xdrive thinking, I guess more specifically the "AGS" specified in rh71's post. But I may be wrong.

but then again, these "problematic" transmissions are all on Xdrive vehicles according to your post...

Bottom line, I hardly notice it anymore. I did get an iDrive upgrade since then..

[nynd]

I thought I read somewhere or saw on a post that when it starts off, its in second (2nd) gear and not first, call it a fuel economy factor. If you put it in "DS" then it gets more lively. I tried to sense the shifting and yes, it seems that for the 4.8 it does start off in two. May explain the so called "hesitation".

[ad78]

Originally Posted by nynd

I thought I read somewhere or saw on a post that when it starts off, its in second (2nd) gear and not first, call it a fuel economy factor. If you put it in "DS" then it gets more lively. I tried to sense the shifting and yes, it seems that for the 4.8 it does start off in two. May explain the so called "hesitation".

you are wrong, the hesitation is not on 2nd gear starts because my 135i starts on 2nd gear on auto mode and there is no hesitation at all. the car pulls like a crazy on 2nd gear.

my 09 E70 3 day old has the exact problem. i bet its the transmission.
i will call my SA on this and probably there is a software update on this problem

[M6X]

i suspect the reason for the hesitation is that in normal D mode, it starts off in 2nd and if you punch on the gas the car has to downshift to 1st to accel.

in DS it just goes from 1st and no hesitation.