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UPDATE 2001 2.7T tip: Transmission Judder/Jerk and Throttle Lag; 2002 2.7T Tip Mode S Test Drive

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Old 01-09-2002, 12:58 PM
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Default UPDATE 2001 2.7T tip: Transmission Judder/Jerk and Throttle Lag; 2002 2.7T Tip Mode S Test Drive

Car Status:
Sadly, my car needs a new transmission. It seems that a solenoid valve seal (previous posts on this on this forum)was not properly seated (assembly fault). Consequently, insufficient viscous forces led to improper engagement causing the judder/jerk. Continued use of the transmission lead to various internal wear issues, principally, the clutches. Snr. Technician now waiting for Audi authorization to replace.

Had excellent feedback/discussion with the technician and service manager. Couldn't ask for more.

FYI: if you feel transmission jerks when accelerating from rolling stops, have the car checked out asap. They may be able to replace the valve with a much shorter downtime. The new valve seals are apparently better assembled. My problems started after 8 or so full throttle accelerations (in D mode)from standstill over a period of about 3 weeks (had to also replace turbo bypass valves and turbo pressure sensor, TBB or Y boot is the modified one and is OK).

Regarding the new S mode and flash programming:
I had a test drive in a 2002 2.7T with steering wheel Tip buttons. I made several starts from standstill, accelerating "gently", "normally" and "aggressively"in D, S and Tip modes, specifically checking the first to second shift. Regrettably, I did not record shift point revs. (would have to be better organized).

In D mode, it still has noticeable hesitation when shifting from first to second, but definitely less than on my 01 car. In S mode, the hesitation is even less, and is still noticeable (since this is what I was testing for!). The shift point is definitely higher than the D mode, but not much...say about a thousand rpms or so. Since we are talking about very small differences, you should check it out yourself. I would definitely say that the S mode has a shorter, more acceptable hesitation and shift motion (smoother)from first to second. The salesman pointed out that it was just a normal shift motion, typical of automatics. He thought it was pretty smooth. I have to agree.

The Tip mode first to second seemed like in D mode. Shifting with those buttons is so intuitive! (Waiting to arrange a suitable time to compare 01/02 system schematics to figure out how we can retrofit tip button wheel to my car. Will report soon.)

General driving: S mode shifts are smoother and quicker than D mode. Same is true for Tip mode (except first to second). S mode shift points are higher than in D mode (of course). I have to say that on my 01 car the Tip mode is noticeably smoother than D mode.

Those with the GAIC Tip chip, please advise your experience, vis-a-vis first to second gear hesitation, general shift motion and speed.

The Snr. Tech will find out from Audi what can be done in the way of reprogramming (flash or otherwise) to take benefit of the S mode features, especially the first to second gear hesitation. They don't think it is throttle lag. More likely it is a software feature to get you into second asap since second gear is apparently preferrable for warming up the engine and catalytic converter (which needs to be at 600 degrees for optimal functioning). Might also have something to do with emissions control and engine longevity. The S mode is available, apparently, due to customer demand.

More soon.
Old 01-09-2002, 01:39 PM
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Default Thanks for the great report. Sorry your going to have the down time with...

the tranny work. PS: was there a DTC or something else that led them to the conclusion they reached ?
Old 01-09-2002, 02:37 PM
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They probably did diagnostics but they ultimately took the gearbox apart.
Old 01-09-2002, 03:35 PM
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GIAC - no hesitation between shifts, quick and smooth
Old 01-09-2002, 05:03 PM
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Default The prob(s) are at low speed, ie, 2nd to 1st and punching from 2nd, eg, traffic...

Did you have this and was it eliminated with the chip ?
Old 01-09-2002, 10:10 PM
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Default Thanks. Looking forward to update on programming '01, and Tip buttons retrofit. Could you...

... link me to prior descriptions (or write anew) about the jerk/shudder from a stop? My transmission (4.2 tip) can lurch from a stop in 1st, but usually only after spirited driving; so, I attributed this to adaption. No shudder noticed.
Old 01-10-2002, 11:02 AM
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Default I thought all 00 and 01 A6 2.7 Tips had the rolling stop jerk.

I have not been able to read up as much as I used to but I thought that all of the 00 and 01 A6 2.7 tips had this problem. I have it on my car and I have brought it up to my dealer and he thought it was a trans chip programming problem and he had felt it on other cars. When I slow down for a stop or a tight turn, but do not stop, and then accalerate I get the big thunk, jerk, like I was hit from behind. I know that it is not good for the car I just thought there was nothing I could do but adapt my driving.

So I should just tell them to check the solinoid valve seal on the Transmission or should I be more specific with part numbers and all.

TIA
Old 01-10-2002, 11:55 AM
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Default What??!! This is unacceptable!!

Clearly, a jerk or thump as you accelerate from a rolling stop or slow turn is not a desirable design feature for a $50k car. So I would not accept this as normal. I did not experience this when my car was new. It developed from normal use. I wonder how many other unfortunate owners are out there? (I will ask by separate post).

My service manager thought it was a software issue but since we are changing out the gearbox we no longer have the opportunity to investigate the software angle (unless the jerk starts again). He and the Snr. Tech that went with me for a test drive thought that the gearbox went into neutral during the slow turn or rolling stop and upon acceleration had to go back into second in a hurry...hence the jerk. It is supposed to stay in second until the car speed drops for it to go to first (but this should be almost at standstill). Since the gearbox is commanded by its control unit, they suspected a software glitch, unless one of the other parameters/sensors (from engine, wheels, etc.) was faulty. Let us know if you are successful.

Now if you also have a solenoid valve seal issue, it can lead to serious internal wear...juddering upon acceleration from a full stop is the physical symptom. Not all cars have the solenoid problem. Ask your dealer to specifically test for it. They might even change out the solenoid if it was one of the affected batch..ask.
Old 01-10-2002, 12:12 PM
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Default Same issue since day 1, ie, 2 yrs ago. Thats why...

I'm so int in your situation. Dealer note has always been "Performs to Factory Specs", "Drive in 4th in traffic". Jerk and thunk still happens occasionally whether in D, 4th, or Tip. Going in for 2 yr Maint Serv soon. Will mention solenoid valve seal. Would be great to know if they did/got a specific diagnostic or anything else leading to the resolution you've reached. Thanks again and pls keep us posted.
Old 01-17-2002, 03:21 PM
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Default Re: They probably did diagnostics but they ultimately took the gearbox apart.

I have the same problem....did they ever fix the jerking and hesitation ?


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