Tiptronic shift problem?

[GranburyChuck]

I have a 2000 C2 coupe tiptronic. I have had the car since mid-June so it is fairly new to me and it is my daily driver. My question is related to the Tip shifting. I usually drive in automatic mode and don't accelerate very hard away from stops. I have noticed that in the shift between 4 and 5 there is an engine rev, almost like a downshift, just before it goes into 5th gear. I am not sure that there is an actual downshift but the RPMs do increase about 500 or so and then drops sometime right around the shift to 5th. Could this be a normal shift program? Perhaps this is part of the electronic throttle reving the engine just prior to the shift. Anyone out there have an idea? I have no CELs. I just rolled past 80k miles.

Thanks

[Izzy]

Doesn't sound right to me. At 80K, have you done the ATF and filter change?

[GranburyChuck]

No I haven't change the filter or ATF yet. I believe that occurs at 100k. Someone thought it might be slipping but I don't get a "seat of the pants" feeling that I loose momentum (me shift forward) when it happens. If anything maybe a slight backward shove of my butt (however that may just be in my mind too).

[Izzy]

I changed my ATF and filter at 45K, and it was worth it. Big difference in smoothness. I was under the impression that the 90K mile replacement cycle has the standard manufacturer disclaimer, to do the maintence twice as often if the vehicle is driven under harsh conditions. The harsh conditions typically include "stop and go traffic, low or high temperatures, dusty conditions, etc". Just a suggestion.

The other potential is pressure regulator 4, which controls the auto shifting from 4th-5th. I had to replace one also, the car was shifting late into 5th.

[GranburyChuck]

I changed my ATF and filter at 45K, and it was worth it. Big difference in smoothness. I was under the impression that the 90K mile replacement cycle has the standard manufacturer disclaimer, to do the maintence twice as often if the vehicle is driven under harsh conditions. The harsh conditions typically include "stop and go traffic, low or high temperatures, dusty conditions, etc". Just a suggestion.

The other potential is pressure regulator 4, which controls the auto shifting from 4th-5th. I had to replace one also, the car was shifting late into 5th.

Did you by chance do the work yourself? If so how difficult? If not how much was it? My drive is long and wide open so not harsh conditions. However, I don't know how the car was driven for the first 75k miles.

[Izzy]

Yes, did it myself. I have step by step instructions in the DIY section. If you got the car with 75K miles, chances are it really needs a fluid/filter change. Not sure how much the dealer charges, but if you have the tools and the inclination, look in:

http://www.renntech.org/forums/index.php?showtopic=6203

[GranburyChuck]

Yes, did it myself. I have step by step instructions in the DIY section. If you got the car with 75K miles, chances are it really needs a fluid/filter change. Not sure how much the dealer charges, but if you have the tools and the inclination, look in:

http://www.renntech.org/forums/index.php?showtopic=6203

Thanks, I had just pulled that up. By the way, what about the pressure regulator change? Did you do that at the same time?

[Izzy]

I had to replace the regulator at 62K miles, so it was long after the ATF and filter change. I would recommend you do one at a time (first the fluid and filter), just in case it is just in need of maintenance. The regulator was about $220 from the dealer.

[GranburyChuck]

I had to replace the regulator at 62K miles, so it was long after the ATF and filter change. I would recommend you do one at a time (first the fluid and filter), just in case it is just in need of maintenance. The regulator was about $220 from the dealer.

Did you get a check engine light when your pressure regulator went bad?

[johnj.moran]

I have a 2000 C2 coupe tiptronic. I have had the car since mid-June so it is fairly new to me and it is my daily driver. My question is related to the Tip shifting. I usually drive in automatic mode and don't accelerate very hard away from stops. I have noticed that in the shift between 4 and 5 there is an engine rev, almost like a downshift, just before it goes into 5th gear. I am not sure that there is an actual downshift but the RPMs do increase about 500 or so and then drops sometime right around the shift to 5th. Could this be a normal shift program? Perhaps this is part of the electronic throttle reving the engine just prior to the shift. Anyone out there have an idea? I have no CELs. I just rolled past 80k miles.

Thanks

I recall reading about this issue on this web-site. Keep searching the postings. Someone that sounded quite knowlegable said this is normal for the tip... something about the nature of the automatic transmission in these cars (viscous this or that, I'm not technical)

Another tiptronic driver suggested not being so easy on the throttle, and you won't get that sudden increase in revs (just a bit more gas than you are currently giving it).

And finally, I recall that another tiptronic driver said that he uses the manual mode instead, and the issue obviously doesn't take place in manual mode.

[Izzy]

Chuck, no, no lights. If you have access to a code reader however, you should read any codes stored. You can have faults without the CEL on for transmission. If you don't have a code reader, many autopart stores will lend you one to read the codes in their parking lot. I think the code I remember having was 0740 for the pressure regulator. But you may still benefit from a fluid/filter change. I did notice a smoother shifting after it was done.

[GranburyChuck]

Had the ATF flushed out and changed by the dealer. Seems to be somewhat better now but I still detect the shift sequence mentioned at the top occasionally. BTW I was charge $390.

[cnavarro]

I usually change my ATF at 25,000 mi; even then, I can tell a difference in how the transmission shifts. I don't believe their use of "lifetime" fuilds :-)

[Izzy]

Did you get a chance to read any codes with an OBDII reader? CEL light will not come on, remember, and you may still have something else going on. Sounds like you did it okay at the dealer if they truly flushed all the fluid (not just drained and refilled) and changed the filter. Filter is cheap, about $35, and would add 5 minutes to the job (remove 1 screw, pull filter out, push new filter in, screw in)

[GranburyChuck]

Filter was changed and they indicated that there were no P codes. However, the service manager had to go back to the tech to confirm that codes were read. Could they be lying???? I had a CEL light for my catalytic converter a couple of weeks ago and Autozone read the codes. Nothing for the tranny.

[Izzy]

The Autozone reader would see it, so you are probably okay.