Dear all, sorry being a middle aged lady with limited knowledge about cars but sporty activities needing a solid car for all occasions winter or summer, so my A6 2.5tdi Quatro Tiptronic from 2004 is now my second of its type.
Just passed the 200,000km mark (approx. 115,000miles) without a problem so far except for the scheduled checkups. However just last 2 weeks suddenly noticed a change of behaviour from its engine/transmission system.

SYMPTOMS:
Situation1:
When accellerating up with gentle/medium power it used to switch instantly from one gear automatically up to the next, with just the expected 600rpm drop for each change. However, now it suddenly makes a little peak up in rpm before really fully engaging in the new gear. So its like its slipping a bit.

Situation2:
When driving e.g. approx. 120km/h (70miles/h) and in 5th gear (marked it is in 5th when switching to manuel tiptronic mode) it is turning at approx. 2,400rpm. Even when just pushing modestly on the accellerator it now revs up to maybe 3,000rpm, but really like not pulling away at all to go faster. It does even at times fell like its gearing down a gear to e.g. 4th, (also matching the 600rpm difference ;o), but when checking by switching over to the manual tiptronic mode it still says that it is in the 5th gear. If I do not ease up on the accellerator it stays often going the 3,000+ rpms, but the speed is not really going faster than the original 120km/h (70miles/h). Going up motorway hills, it can at times not go faster than the 120-140km/h(70-80miles/h) as the rpm goes up to 3,300 (and the gear indicator still says 5th).

THE GARAGE:
My garage said that it probably just needed a change of oil in the gearbox (transmission?), so paid dearly for that. But result is no change what so ever.
Is the Tiptronic gearbox and clutch all in one piece or was this oil change they did only for the gearbox? And why did they not talk about the clutch? Is that the torque converter I have seen mentioned a few places on this forum?
The garage then said next step would be to change the entire gearbox, but the price seems very big (6,000EUR/$8,500) here in Europe. Can this problem really only be the entire gearbox one has to change or could it be something else?

Thank you for any advice you can give.

Kind regards
Renee

 

The torque converter is the auto equivalent for a clutch. Are you taking it to a dealer? I find 8500$ for a gearbox crazy especially since slippage doesn't come front the gearbox at that mileage on an auto. BTW I would be careful when talking to a shop. As a middle aged woman they may lead you on and charge you an arm and a leg assuming you are none the wiser. Find a good independent, for 8500$ you could buy a new car.

 

Thank you jhuffman !
Yes indeed I am normally taking it to the authorized AUDI dealer/garage, which I actually have done through the car's entire life. I have at times also found even the standard mileage revision checkups quite expensive, so I know what you mean about expensive. Now I do live in The Netherlands where the cars are all quite expensive due to special state luxury taxes and high labor costs, so my car would probably still cost maybe $20,000 as second hand. Would you based on the symptoms I mentioned believe it would be the torque converter that should be changed instead and not the gearbox? Btw does the torque converter tell the gearbox to change up or down? Maybe that can then also explain why I feel it changes down too easy and also not changes up again when really no pull is required (experience really only when in 5th and it seems to change down. No obvious trouble in accellerating from standstill and up through the gears to 4th, though it may go higher in rpms compared to earlier).

I have at times had some strange electric/computer problems with this car in the past (seems to have messed up or forgotten som settings, e.g. radio/tv program settings, door anti-carjacking settings, remote key user settings, etc) but the garage has then after hooking it up to some sort of computer been able to get it back to normal behaviour again. Any chance that these symptoms could entirely be due to an electronic control or sensor problem?

Not sure how to find a good independant that I can trust, so feel almost obliged to take it to an AUDI garage. (too old fashioned? ;o)

Thanks again for any comments/advice you can add.

 

A middle aged Dutch Lady with an Audi! Oh you’re a Dane! In either case - Will you marry me? Just kidding - LOL

As huffman says the torque converter is the connection between the motor and transmission and replaces the clutch on a manual vehicle. It slips at low speeds and on some vehicles locks up when you get going fast. On the other hand the automatic transmission has a number of different gears that are controlled by clutches, hydraulic fluid, and electrical solenoids.

Changing the fluid sometimes helps when the transmission is acting funny because small amounts of dirt can slow the hydraulic fluid or plug up small orifices. Other times the clutches get worn and there is little you can do to fix the problem except rebuild the transmission.

The jump in RPM in 5th gear could indicate that the torque converter is not locking up correctly but there could be other causes.

Then there are the electrical problems - weak solenoid, bad signal, flaky sensor that can cause problems. The tiptronic is a bit of a mystery to me but your computer problems indicate that you might have an electrical issue.

The only way to know for sure is to have a highly trained Audi specialist diagnose the problem with the correct tools. If you’re questioning your current mechanic, it doesn’t hurt to get a second opinion from a different Audi mechanic. If that leaves you confused don't give up try a third. Remember -your making a $8,500 decision and it is best to find the best answer.

Maybe Auditech79 can give his opinion – he very knowledgeable and has been a big help to many of us.

 

If there is anything I have learned while owning audi cars its start small with repairs and work your way up. I've read the tiptronic tranny is very solid and I wouldn't believe that it would be the internals going bad. Flush the tranny fluid and check solenoids and computer. The computer controls everything through the solenoids and hydraulics. I still suspect torque converter, but again, thats a tough part and unless you totally rag on your car its probably something smaller.

and like NH says, get different opinions before making a huge commitment. Just use the internet to find another mechanic, or a phonebook. Audi is a common enough car that you should have at least a few other options