Annoying roll forwards...

[Hippogriff]

Although I do understand this is not how one should drive, I have - over 2 previous A4s (a B6 and a B8) very much liked the fact that my car has exhibited good crawl and hold features, on any gradient.

For example - the B6 and B8 and the new facelift B8 all behave well when facing upwards (car pointing forward on an upwards incline)... if I take my feet off the pedals I know I'll never roll backwards. I have utmost confidence in this, no matter what the gradient might be (well, the steepest I've tried anyway).

However - in the B6 and my previous B8, I also had this confidence when facing downwards (I mean, the front of the car is lower than the back of the car)... in the new facelift B8 that is not the case. I have been frustrated by this in the driveway... where, before, I used to be able to lift my feet up and the car would start to slowly crawl up the incline in reverse, now, when I take my foot off the brake, and it is in reverse, the car will roll forwards.

So, I tested it on an empty road... I parked-up on an incline, facing downwards, and I started the car (obviously with my foot on the brake), and put it into reverse... when I took my foot off the brake it held position for about 1 or 2 seconds, then started to roll forward.

I did not expect this to behave this way... has something changed or did I always have 'special' A4s before? As I say, my previous A4 was also a B8.

[Zenerdiode]

Hello Hippo,

Nowhere in your post or signature does it state what type of transmission you have! :)
I'm presuming an automatic and guessing DSG...?

[Hippogriff]

Soz, they've all - B6, B8 and facelift B8 - been multitronics. I just assumed everyone would know... :Blush2:

[Zenerdiode]

Ah, OK. The reason I asked is that I recently had a 2.0T TT as a courtesy car and that had a DSG gearbox. It behaved exactly as you described above; and my reasoning is as follows:

The clutch(es) is effectivelly an electronically controlled manual clutch - rather than a hydraulic torque converter. If you are on a flat surface and snick it into 'D' the car will take up drive and continue as long as you let it. However, if you foot brake to a stop, it will slip the clutch for a few seconds, then dis-engage entirely. Lift your foot and it senses the brake-light switch switching off, slip then re-engage the clutch and you're off again.

The problem arises (and for me completely took the shine off an otherwise very good car) when you encounter a steep hill. I have one on the way home and at the top is a T junction and was quite tricky to drive smoothly. As described, at the top waiting to pull out, you'd expect to footbrake to a stop then the 'creep' would hold you. It does, for about two seconds, then the TCM must worry about burning the clutch and dis-engages it. This caught me un-aware and had to quickly stomp on the footbrake. When you lift from the footbrake to go for the gas there is again a bit of roll-back. I tended to give too much of a jab on the gas to compensate for this and subsequently lurched out of the junction like a learner or wannabee 'look at me in me first Audi'. Next time I thought I'd hold it in 'D' on the handbrake. This was even worse as this time, with no footbrake input, it's obvious there's no handbrake input to the TCM and so the 'creep' literally dragged the nose out of the junction and I had to stomp the footbrake again.

I learned the smoothest way of doing things was footbrake to stop, drop to 'N', handbrake on then rest your feet. Moving off was footbrake on, 'D', release handbrake, release footbrake and gentle gas before the two second clutch dis-engage.

Perhaps you could try that and maybe someone may comment on what type of clutch is deployed in the new Multitronics?

[fat controller]

I've seen some bus/coaches behave in the same way, and its apparently a 'feature'- not entirely sure what the perceived benefit (other than perhaps reduced wear on the gearbox?) - I've even had similar symptoms with some ZF autos on buses in forward drive; if sitting stationary with foot on footbrake, there would be a couple of surges as though it was attempting to pull through the brakes, before then disengaging drive completely; when lifting off the brake thereafter the vehicle could roll in either direction before the vehicle 'twigged' that drive was now required at which point it would take up drive with a bit of kick.

[b206]

The multitronic box is crap - possibly the worst Audi have produced.
I swapped my B7 for a V6 B8 which has the S Tronic box (looks like Audi continued the Multitronic into the TDI B8's only?) - whilst this is a better gearbox is still has issues although the opposite to what you describe. When on a hill, it will roll backwards until you give it a bit of gas - but in reverse uphill it will slowly crawl.
I have the luxury if "hill hold assist" so not really a problem - but I can see it being a pain especially with a frigging electronic handbrake as well!

[SunnyBard]

The problem arises (and for me completely took the shine off an otherwise very good car) when you encounter a steep hill. I have one on the way home and at the top is a T junction and was quite tricky to drive smoothly. As described, at the top waiting to pull out, you'd expect to footbrake to a stop then the 'creep' would hold you. It does, for about two seconds, then the TCM must worry about burning the clutch and dis-engages it. This caught me un-aware and had to quickly stomp on the footbrake.

This is where the Hill Hold Assist really comes into its own, as soon as you come to a halt and the green brake light comes on, feet off all pedal until ready to start off again.

[Hippogriff]

I played with this a bit more...

No A4 that I've ever had - B6, B8 or B8 facelift - has ever rolled backwards when facing up a hill, and in D, I can confirm that I have never had Hill Hold Assist and I don't see the point in it. It really isn't an issue for the car to roll backwards on any hill, it never does, that's not my concern... I can assure everyone that none of the three A4s I've had ever rolled back (including this new B8 facelift) and that's even on some very steep inclines.

Although I knew this anyway, I can confirm that, yesterday, in the new B8, I came to a complete stop on a steep hill, facing upwards, in D, and the car would not roll backwards. Sadly, unlike my previous B8, it would just hang there, it would also not crawl forwards. My previous B8 would definitely start to crawl forwards even on the steeper hills, so there is a difference in behaviour here. However, the key point is - it didn't roll backwards and I'm OK with that.

The two previous cars would also not roll forwards when in R and facing down a hill, but this one most definitely does. It is scary (because I've become indoctrinated as to how I expect the A4 to drive - having had two other A4s for over 8 years!) and I really do not like this at all. As I was experimenting yesterday, I looked into this for a few minutes... when in R and facing down a hill, feet off pedals, the car mostly hangs steady for about 2 seconds, before starting to roll forwards. But there were also times when I took the foot off the brake and it started rolling forwards straight away, I think it might be related to how quickly I took my foot off the brake... I genuinely dunno.

Commenting on the multitronic gearbox itself is not really useful in this case, because all three A4s I've had have been multitronic - although it is interesting that the S Tronic box appears to behave in an opposite manner. Quite simply put, my issue is that this B8 facelift behaves differently to the previous two A4s (one of them also being a B8!)... that has surprised and disappointed me, I need to change my - admittedly crap - driving style to accommodate this car.

Obviously, it's not really an issue when actually driving, but it becomes an issue when manoeuvring, especially if things are very, very tight, I don't feel I can get as close to something (a wall?) at the front, when turning around in a tight space, just in case the car goes forward rather than backward when I'm about to continue to turn in R.

It is annoying me so much that I'm wondering whether Audi can flip some magic bits and make it operate differently. :confused: Really doubt it.