Tiptronic change playing up- A6 2.5tdi Quattro Avant : AFB 136,500

[JohnG60]

Just would like to know if anybody has had a similar problem

Car was serviced about 6 weeks ago by VAGtech and I had the tiptronic gearbox oil changed at the same time (first time it's been done)

Since then the gear changes in Auto/Drive have been much smoother and consistent. However in Tiptronic mode it’s sometimes getting itself into a bit of a pickle.

If I drive relatively sedately changing using the tiptronic all is fine, but if I push on a bit with higher throttle and changing at around 3500 RPM it will go through 1^st – 2^nd and 3^rd through to 4th with no problem but then when going from 4^th to 5^th it won’t hold 5^th gear and immediately drops down to 4^th indicated on the DIS, although it’s not actually in 4^th but sounds like it’s running via the torque converter (revs too high for 4^th at indicated road speed) if I try to change up again to 5^th it won’t do it – DIS goes to 5 and then immediately drops back to 4. The only way to stop it doing this is to put it back into D and slow right down and it then seems to sort itself out.

I've booked it in with VAGtech next Thursday but just wondered if anybody knows what this could be and am I going to be looking at a large bill ?

I've had the car 8 years now and we love it but the last 18 months it has cost over £4,500 in repairs. A 3-4 year old 3.0 TDI quatttro avant C6 is looking more and more appealing...............

[Mike B]

As there has been no comments so far I thought I would ask why you had the fluid changed and whether they assured you that they knew the drill.I have an A4 same spec and its been to Audi for a refill after someone drained the box accidently. It does drive better with none of the problems you have.I heard that the box can program itself so maybe the controls have been unsettled.Hope its not going to be big trouble and would be interested to hear what they say

[JohnG60]

Hi Mike

Thanks for the comment. I decided to have the fluid changed partly as a precaution (I'm not a great fan of "filled for life" oils) due to the age an mileage of the car and also because the gearchanges in D had been getting a bit sloppy (sometimes not changing up early enough) although nothing major and in Tiptronic it has always been spot on. Since the oil change the gear changes in D have improved massively.

I was very much aware that to drain, change the strainer and refill was not a simple put the pipe in and fill it up job. But they assured me they do it on many Audis that come in so I assume they cycled through the gears correctly at the right temperature to get it re filled properly.

Over this weekend I took it out for a fast 100 mile run just to clarify where the problem is - It happens if I'm driving enthusiastically in Tip/manual and down changing for engine braking on bends and roundabouts and then accelerating out on high throttle, so the gearbox is actually working pretty hard prior to the problem occurring.

I'm hoping it's something simple like a low level where they haven't actually refilled it fully or as you say an ECU gearbox program glitch.

I't's booked in Thursday morning so will see what fault codes are showing up - and hopefully it's not going to be a big problem......

I'll post the outcome on here as it might help somebody else if they ever get a similar problem.

[JohnG60]

Update -

Went up to VAGtech yesterday - no fault codes showing up on the diagnostic at all. they took it out for a test drive with the VAG-COM connected and even though they managed to induce the same problem still no fault codes showing up. They re checked the fluid level but all Ok there. A big thank you to Victoria, Jon and Ben for the excellent service again (as usual).

The opinion at the moment seems to be there could just be wear in the gearbox and the ECU is somehow trying to compensate - It drives fine if I'm just cruising around.

To get the gearbox reconditioned is about £1,400 plus fitting on top. On a purely pragmatic view it probably doesn't make sense to spend any more money on the car, the last 18 months it's had cambelts done, both fuel pumps replaced, A/C condenser fan, track rods and a few other bits and bobs.

The trouble is I really love this car and we've done some serious touring in it over the past eight or nine years - it's just part of the family. I've looked on Autotrader for a 3-4 year old A6 3.0 TDI quattro avant around the £15k mark but just don't like anything I see. There are loads if you like anything in several shades of grey, silver or black with black leather, but every second car on the road these days is a shade of grey, silver or black and it's just not for me - personal preference . (Mine is pearlescent racing green with beige leather and walnut with just about all the extras of its year, )

I reckon for half the money (£6k-7k)of a replacement I can get it back to running how it should - Looking to get the gearbox recon'd - get a custom exhaust taking out the main cats (no starter cat on the AFB - are they cats or DPF's ? workshop manual calls then cats... ) and then re map it, shocks and bushes - possibly a respray as well to get rid of 10 years of car park nicks and scratches.

Decision not final yet but I think that's the route I'm going to take -

Is it worth me upgrading the turbo ? if so to replace with what ? If any body has any thoughts or comments please feel free to post.

[Mike B]

This is often the dilemma with cars as they get older ....are they turning into a moneypit or do they justify the expense?The most important point is if you spend a lot more money would you expect to keep the car for long enough to get the same pleasure that you have had so far?Otherwise this sort of money is too much

[JohnG60]

I totally agree with you.

It's a question of me weighing up a number of factors - unfortunately whatever car we drive there is a cost involved, be it maintenance or depreciation.

I'm not a great lover of the C6 avant, never have been. I just don't think they got the shape quite right. I had a good look over the new C7 avant (4G) last month at my local dealers and I do like that one. However the model I would want is the 3.0 tdi twin turbo (309 bhp and 479 lb ft) which is not even available in the UK until next year. By the time I've added on options that I would want the price is not far shy of £60k - and then watch it depreciate by 40-50% over the next 3 years - That's too expensive for me to justify at the moment.

So I need a car for the next 3-4 years until the new C7 has had the main depreciation hit down.

I can buy a C6 3.0 TDI quattro avant for let's say £14k and use it for 3 years and add 45k miles on the clock by which time it would be worth maybe £8k so depreciation cost will be around £6k, that is before any maintenance or repairs costs during that period.

Or I can spend that £6k on the old girl and keep her running for another 3 years or so.

decisions decisions ...........

[Mike B]

Seems to me that if you like this car and can envisage keeping it for a few years its worth sorting out.That way if the box is 100% it would be a good selling point.My reservation would be getting an expert recon done but hope it wont cost anything like £6k to sort and you will be able to get areplacement where someone else has suffered the depreciation

[JohnG60]

Agreed Mike

It's going back up to VAGtech next month to have the crankcase breather valve (oil separator) changed and clean out the inlet manifolds and then a re-map- probably from Celtic Tuning. I want the emotion tuning option as it enables me to switch between standard - economy and fast road map. I will leave the gearbox for now as it's not a huge problem and if it does give up then the AA have to contribute £500 towards the cost under my Breakdown Repair Cover

[Mike B]

Hope it all works out