S4 S-Tronic 'Issue'

[Dr_Rick]

Bit of background first I think. Car is an 09-plate (2009) S4 saloon that I picked up in July with 72k on the clock. As part of the deal I had the indi dealership do a gearbox oil change for both gearbox and mechatronic units. The car had been serviced about that time separately too. Right now, it's sitting with just over 77k and I do around 65miles per day, 5 days per week for commuting on the motorways (Edinburgh to Glasgow effectively). Car is standard without DRC or Adaptive Steering.

So, to the 'issue'. I've noticed more recently that when coming to a halt at the lights, typically first thing in the morning and when the car is cold, I get a jolt when the car downshifts from D2 to D1. I'm usually stationary when it happens (about 0.5s after actually stopping). It doesn't happen if I'm using the flappy paddles and already in D1. I use the Hill hold to keep the car from moving in these sort of situations to save blinding the person behind with the brake lights.

During the day the car doesn't move, and the return commute doesn't really have the start stop with lights and roundabouts when the car is cold as I leave Glasgow and may not encounter stationary traffic until the outskirts of Edinburgh so the car is properly warmed up by then.

Given it only happens in full auto, my gut feeling is some sort of software issue as the changes are smooth in manual and the Hill hold transitions are fine. I don't think it could be the mechatronic unit itself as I would have thought that the actuators would cause jip in both manual and auto if they were starting to die.

I'd get it into Audi, except that their £60 diagnostic for an hour initial offer was swiftly replaced with a 'We need it for 5 hours and after the first hour our rates go up to £100+', so it would be nearly £500 or a checkup. I have an RAC Warranty (came with the car), and I've got it booked in to a local specialist for a look-see on Monday, but does anyone have any thoughts?

[Dr_Rick]

Can an indie specialist do this, or is it only available from Audi main dealers?

I'd rather pay an indie for a diagnosis and gearbox flash than pay £500 to get Audi to do exactly the same thing.

[Dr_Rick]

CerberusRogue said:

I had this issue on an S5. Audi did the software update but in the end changed the mechatronics. Then it failed again so changed the gearbox! An extreme situation probably compared to yours though.

Might be an idea to ensure you have the extended Audi warranty!

Car came with a non - 'extended Audi warranty' when I purchased it. Just ran a quote up and it came out at just over £1300. I know a mechatronic box is about £1500 to change, and the gearbox is about what £7000 to change including the mechatronic box. I kind of figure that a software flash is a good start.

My main problem is that the warranty I have excludes design faults. Ideally, I'd like this to fail spectacularly so a replacement is the only option.

[Dr_Rick]

Well that's all a bit depressing then isn't it...

[Dr_Rick]

Asked when trying to book in; nothing outstanding apparently.

[Dr_Rick]

So, a colleague came over and did a fault read. He came up with:



What does that mean I need to do now then?

[Dr_Rick]

Adaption done. Will see what its like over the next few days. Otherwise, its mechatronic time

[Dr_Rick]

So the clunking is still there.

I've had a discussion with a number of independent garages that deal with Audi's and have had a number of different responses:

1 - Mechatronic unit on the way out
2 - Check the gearbox oil for glycol contamination from the gearbox cooler breaking down (new gearbox needed in this instance)
3 - Clutches
4 - Oil flushes needed

And for those that have any interest, my quotes so far for the mechatronic replacement is effectively £3,200 all in (£2,600 being the mechatronic unit alone), and a radiator / gearbox change being £9,850 all in.

Does anyone know if mechatronic units can be repaired? My warranty company indicated that they had a company on their list (whose name I've managed to forget - begins with an 'S' though) who could repair them.

[Dr_Rick]

Yours appears to have the two tone interior, so it's definitely not the same car.

Did your gearbox get changed under warranty (either part covered or completely covered)? My problem is the lack of FASH and a distinct lack of first gearbox service at 38k - i.e. no goodwill coming my way. Plus the fact I've done best part of 6k miles since I bought the car in July which means no point going back to the vendor. Allied to a single claim limit of £2k.

If the gearbox has gone, I'm unsure of what I should do except stump up about £8k, or half the price I paid for the car. I know it's all a lottery with cars, but that doesn't make it any more fun.

[Dr_Rick]

TO get an Audi Extended Warranty would cost me £1300 for the year. I got a 2yr RAC Gold Warranty with the car for 'free'.

[Dr_Rick]

Indeed.

Well, in a turn out for the books, over the last week I started by giving the car a few runs in manual and then for the last few days the auto runs have been smooth as. The garage did tell me it would be a few hundred miles for the Adaption programmes to settle down and maybe they were right.

I'm not going to get it 'fixed' this side of New Year as I don't fancy paying out over £3k then trying to get my refund from the warranty company over the holidays. I'm now going to see how the box performs; if it stays as it is now, I'll leave it, otherwise January it is.

Fingers crossed!!

[Dr_Rick]

There's got to be an indie specialist somewhere near you who can do a diagnosis cheaper than the main stealers. My adaption run and a diagnosis scan via three different systems cost me about £75 all in. I bet Audi would have charged a out more!!