2006 tiptronic 6spd auto behavior

[BrianJ]

I have a question that others may be able to answer about the tiptronic.

Its a bit difficult to describe so bear with me.

Recall that some autos have lock up torque convertors, and when they lock the torque convertor slip you can detect a drop of revs in the order of about 500 rpm, this was very noticable on the RAV4 4spd where it would unlock as load was increased like going up a hill, then when load reduces it would lock again. Similairly when going through the gears, the gear would change firmly then a few seconds later you could notice the extra rev drop when the torque convertor locked.

Back to the tiptronic; When mine changes up after starting off in 1st it will change firmly to 2nd with no flare, and no other rev change, but when it changes into 3rd it changes firmly again, then about 3 seconds later the revs drop about 500rpm, with no flaring up of revs at any time, then into 4th same as second just one single operation, same for 5th and 6th.

This double rev drop is the only odd thing I notice about it. I have reset the controller a couple of times and it makes no difference. I can't find any technical detail on how it should work, and I am fairly sure it has always done this from new.

If anyone knows anything technical about these boxes could you give an opinion on this operational behavior.

Thanks
Brian

[Silver Caravelle]

Hi Brian,
I recall the the Tiptronic has partial lockup to full lock up in third ( I think also second?). And full lock up in fourth, fifth and Sixth. I experience the same as what you do (the 500 RPM drop once going from partial lock up to full lock up). It is noticable under light acceleration then goes into lockup. Under heavier acceleration, it appears to go directly full lock up.

Regards,

Scott

[Sunny43.5]

All I will ad here Brian is if you have not had the auto ever serviced and are contemplating having it done MAKE sure they remove the sump and replace the filter critical as it become blocked and causes all sorts of mayhem and then destruction as was the case with ours .

[BrianJ]

Thanks for the advice Sunny, I did follow the saga of yours and because of that i did have the oil changed, but did not do the filter, partially because there had been no malfunction so hopefully no friction and burning causing disintergaration of the clutches material. The other reason was that I was a little afraid of disturbing sleeping dogs as the saying goes.

Interesting feedback also from Silver, that his does the same thing as mine does in third. As I usually nurse mine, it would be mostly light accelleration and that's when the trait shows up. It would be interesting to learn a lot more about the operation of these autos to be able to know what is normal and what is not.

Brian

[Cousin]

Mine does the same, Brian
2006 Multivan Highline
It's had two rebuilds in the time I've had it and has behaved the same each time (as you describe)
So I have to assume it's normal
I liken it to selecting the gear before it actually engages it
But sometimes (going up a hill) it won't engage the gear it's showing as selected
Sort of like riding a clutch, which I guess sometimes it has to do
Doesn't seem to cause a problem, and if it's a bit hilly and likely to do it more, I put it into sports mode
Holds the revs longer and is more definite in it's gear selection then


M

[Sunny43.5]

Look Brian as a matter of interest in my own opinion the main problem with these boxes is that VW believe that they do not need to be serviced and from my experience this is not the case . If I had known what I do now I would have demanded at the first hint of problems that the sump be removed and the filter changed . Our T5 was not abused was not driven hard and was serviced by VW up to the point when they spun me the crap about sealed for life . I know lots of members have had no problems with theirs but I would guarantee you that there were dozens more who probably paid out big bucks to have theirs fixed and no one knows of these people on this site !
There has to be some sort of wear and tear within the sealed confines of the box and there has to be a time when this material will always end up in the filter and this will lead to blockage , and the first sign of flaring slipping etc is the time when the debris will start to accumulate and will progressively get worse with more slipping and so it escalates with the end result that it will cause a major failure . I would love to have the money to pay some experts to test the oils as I am sure it would find VW culpable for the failures of any sealed transmission built this way .

[BrianJ]

It is not known yet whether certain boxes would fail even if the oil was changed every 10,000k. I agree with your point that once some slipping begins then it is an accellerated time until complete failure due to filter buildup. I don't doubt that you drove yours sensibly, but maybe from new one clutch was adjusted wrong, who knows, I don't even think VW knows what is the cause. Of course there is no harm in changing the oil, that's assuming the service shop puts the right oil in the box ! There is a lot of risks with machines as complex as these especially when not living in a country of origin and there are very few experts. It is shocking to read the UK forums and see how much damage is being done to these vans by lack of knowledge, and it is because of this that I have my theory about leaving things alone if they are working.

Lets hope we all have future reliability.
Brian

[Silver Caravelle]

Thanks for the advice Sunny, I did follow the saga of yours and because of that i did have the oil changed, but did not do the filter, partially because there had been no malfunction so hopefully no friction and burning causing disintergaration of the clutches material. The other reason was that I was a little afraid of disturbing sleeping dogs as the saying goes.

Interesting feedback also from Silver, that his does the same thing as mine does in third. As I usually nurse mine, it would be mostly light accelleration and that's when the trait shows up. It would be interesting to learn a lot more about the operation of these autos to be able to know what is normal and what is not.

Brian

Hi Brian, to clarify further, I read somewhere, gears (second to sixth) will lock up with the torque converter depending on the load and acceleration. This is what you are experiencing when the the revs drop (going into lock up). It is not flaring and mine has behaved this way (as it should) since new. There is a VW (Aisen) self study document on the net regarding explaining how these autos work. I will see if I can find the link.

Regards,

Scott