S3 PFL... confused S-tronic gearbox?

[LJC105]

Hi all,

I've now had my new (to me) S3 for over a week now.

Every once in a while the S-tronic gearbox gets freezes for a few seconds when downshifting into first gear at speeds of 20 and under, something that's proven to be incredibly unsafe at the worst of times! After a few seconds the car gains back momentum and sends me back into my seat.

I was downshifting to first at a roundabout as I'm braking, foot off the brake and my car slowly coasts onto the roundabout... on a 50mph road

I thought this was a case of the gearbox not being able to cope with first gear (it could well be, please do let me know) until this afternoon going from a 50mph average speed back up to 70 on the M6... as I see the national speed limit sign I put my foot down and the car gives the exact same 'freeze' it previously did in manual mode, this time being in sport mode.

This was incredibly dangerous as I was merging into the right lane as this was happening and I had someone coming up behind me. It picked itself back up after 3 or 4 seconds. It felt like the engine cut out.

I'm really hoping Audi haven't sold me a lemon which has been known to previous transmission problems. Has anybody else experienced similar?

 

[Tom.H]

Personally I never really shift into 1st, I've always let the car do that itself. I've found so far with the S3 and the R32 that they stay in 2nd until you're almost at a stop and will then shift into 1st.

 

[TYb]

The facelift tends to stay in 2nd until around 5mph or lower, I wouldn't force it into 1st at 20mph.

Sometimes when flooring it they can hesitate as at 50 you could be dropping from 2 to 3 cogs, the box can't have them all ready and waiting. In situations like that you are better dropping a gear before you need to take action.

 

[RichardT]

I don't use manual and it more or less never shifts down to first.
I think you are seeing the hesitation often described and something that needs getting used to.
But your description does sound a bit extreme compared with mine.

 

[steverobertsbbc]

As I'm sure you're aware, the DSG gearbox is a dual-clutch system, where one clutch is driving the car whilst the gearbox behind the second clutch has what it calculates to be the next gear set up behind it, ready to swap clutches at a gear change. If you're in second and going at about 20mph, it's reasonable to assume that the gearbox will have pre-selected third on the other clutch, as it doesn't normally drop to first until the speed is very low. However, if you manually force a selection to first, then the gearbox has to deselect third and reselect first before it swaps clutches. There is a significant delay in this happening, I wonder if that's what you are experiencing?

 

[LJC105]

Thanks for the response guys, I've just looked back on the dashcam footage, interestingly enough it seems the gearbox chose the wrong gear on the kick down and made it bounce off the rev limiter..? I never knew this was possible in these types of cars. You can see here:

 

[Flying Scotsman]

As others have stated the DSG transmission in auto mode will not shift down to 1st gear until you are almost at a stop. Changing into 1st gear whilst in manual mode at a speed of 10-20mph and flooring it will get you no speed advantage over leaving it in 2nd gear and letting the torque of the engine do it's thing, in fact you will probably be slower in changing to 1st gear
The engine's torque band is your friend....high revs gain nothing for this 2.0 litre turbo engine.