DryHeat 2.7T

Got my car back today. New transmission installed. Acceleration problems addressed.

TRANSMISSION:
No hard jerk/thump when accerating from running stop or during slow turns. However, at times there is still a "noticeable" jerk but it is much, much better (less) than before. I say noticeable because I was looking for it. This "lesser" jerk/thump is also present when stopping, i.e. just before the car comes to a complete halt the transmission goes into neutral and a slight jerk can be felt.

1st TO 2nd HESITATION:
It is still there as large as life. Seems to be less noticeable when accelerating gently (probably gives the transmission a bit more time to engage smoothly). However, I now notice it in all gears whereas in the old transmission it was 1st to 2nd!! The hesitation in the higher gears, though noticeable, is not as severe as from 1st to 2nd and I could live with it (seemed much like the loaner Taurus I've been driving around!!)

ACCELERATION/TURBO/TURBO BYPASS VALVES:
The car certainly seems more spirited now. However, with gentle acceleration, there is a shrill screeching or chirping sound (not whine) and its pitch seems to be in sync with the revs and shift points. With hard acceleration, this chirping becomes evident much further up the revs and seems less loud (may be the louder engine noise from acceleration masks it a bit). In the first 4 - 5k miles from new, I remarked on the absence of any turbo whine or other noise (all previous turbo cars I have driven had a whine). So this chirping seems to imply that all is still not well. I know that with higher mileage, there might be some whine ...but chirping??

Without back to back comparisons I just have to be happy with the more spirited performance. I was assured that they took great pains to check for leaks in the intake system and none were found. I vaguely remember reading somewhere on this forum that bad turbo bypass valves can emit such a sound. Can anyone help? Both my valves were replaced.

Incidentally, when first starting the car (cold engine) the secondary air intake system operates and then shuts off when engine temperature rises. When this happens the car makes a loud deep throbbing noise which stops when the system cuts out. I was told the cold outside air temperature was the cause and that in the warmer summer temps this would not be the case. This was another reason why I wanted them to check the system for leaks. Members in real cold climates in the north, can you check this on your cars and report? Thanks.

TRANSMISSION CONTROL SOFTWARE:
The Snr. Tech., who took care of the car, and I had a long discussion about the transmission and hesitation. He confirmed my own findings from his own test drives and had been in touch with the Audi and ZF people in Michigan regarding software updates. He thinks it is a software issue. We now await a response.

I did tell him there were many owners facing the same issues and that a couple of forum members had reported that a new control box (with presumably revised software) had largely eliminated the jerks and hesitation. He would like those members (with the new control units) to please indicate who their dealers are, any part numbers, date of service or other info that would help identify the revised units. (Please email me and I will forward the info). The Snr. Tech indicated that the Audi people were behaving as though it was a new situation!!! Your info will help Audi obtain the relevant info from your dealer and then, hopefully, formulate something for all of us affected.

Many thanks.

DryHeat 2.7T

Regarding the solenoid valve seal: There are 8 solenoid valves in the transmission. The one that caused all my problems is the one "that transmits fluid pressure". Any one familiar with the Tip transmission will know, I guess!!

It is known that the design created difficulty in assembling the seal onto the unit. So when the tech drove my car he had a hunch that that valve could be the cause...and he confirmed it by stripping the gear box!! I forgot to ask him if there was a specific Audi test procedure...I will ask tomorrow and find out a p/n. My car would judder upon acceleration from standstill, as though there was clutch slippage. Because the errant solenoid is responsible for transmitting fluid pressure to cause mechanical clutch engagement, the judder (grinding sound) was indicative of its malfunction. So if your transmission is somehow low on fluid, there could be trouble brewing such as "jerks" !!

The jerk by itself is reckoned to be a software issue. If the software doesn't clear it up then suspect the solenoid valve seal (big job!)

timcar

my understanding is that there is a revised PROGRAM that addresses the Tip issues you've been having. I don't know the details, but recall other posters saying they got a new program. I assumed this program resided in the Tip chip, but whether they actually replace the chip, or simply reprogram, I can't say. Hopefully, someone who's actually had this done will respond with the info. you requested

derfA8L

...retrofitted on customers' cars. To my knowledge, these units have not yet been EPA certified. I got my dealer in trouble with AoA for posting a similar conversation with my service dept. after ZF had installed one of those re-programmed units in another customer's A6. Until these new controllers receive EPA certification, it's doubtful Audi,or ZF, will officially acknowledge their existance.