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WOT auto shift problem(?)

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Old Nov 15, 2011 | 08:12 PM
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Default WOT auto shift problem(?)

2008 Base Auto - 33000 miles. Cruising at 70mph today - floored it. Trans shifted to 2nd and reved to about 5500 - would not upshift (and ergo accelerate) until I let up on the throttle. Works fine with "more normal" half throttle downshifts. Some threads seem to indicate potential leaking seals - others say this is due to tire spin (at 70mph?)
Anyone having similar symptoms?
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Old Nov 15, 2011 | 10:08 PM
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Originally Posted by RAW1
2008 Base Auto - 33000 miles. Cruising at 70mph today - floored it. Trans shifted to 2nd and reved to about 5500 - would not upshift (and ergo accelerate) until I let up on the throttle. Works fine with "more normal" half throttle downshifts. Some threads seem to indicate potential leaking seals - others say this is due to tire spin (at 70mph?)
Anyone having similar symptoms?
It happens in higher gears when you press hard on the go pedal with the A6 tranny unfortunately. It's one of the reasons I always drive with the paddle shifters.
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Old Nov 16, 2011 | 07:13 PM
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Originally Posted by DSOMC6
It happens in higher gears when you press hard on the go pedal with the A6 tranny unfortunately. It's one of the reasons I always drive with the paddle shifters.
Our 2009 A6 is now at 39k miles, and we've never had a problem with upshifting unless the rear wheels were spinning or the car had hit the rev limiter (only in paddle mode).
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Old Nov 16, 2011 | 07:33 PM
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Originally Posted by Gearhead Jim
Our 2009 A6 is now at 39k miles, and we've never had a problem with upshifting unless the rear wheels were spinning or the car had hit the rev limiter (only in paddle mode).
I don't think he's refering to upshifting. What happens is when you are cruizing along in D or S at low rpms in say 4th/5th gear and step on the accelerator hard enough to downshift, many times the tranny will drop down (downshift) too many gears causing the engine rpm's to skyrocket.
In his case it went from whatever gear he was in to 2nd gear at 70mph! Its happened to me more than once. That is why I don't trust the computer to choose a gear for me when I want to downshift. I always use the paddles to avoid a possible over-rev.
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Old Nov 16, 2011 | 09:08 PM
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Good point.
We've never had the tranny select a "wrong" gear, bur sometimes it needs to upshift pretty soon after the downshift.
We've never had it act like the trans went into neutral and just let the engine rev freely, but others have reported that issue.
We are quite happy with tranny in our 2009 A6, but the 2006 A6 we had previously was not quite so good.
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Old Nov 16, 2011 | 09:32 PM
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hmmm, I dont know! were you scared to red line it? in sport mode mine will shift into second at 65 mph then rev to 6600 rpm and shift into third at 76 mph. try it again and hold it on the wood till it shifts. in D mode it will shift into 3rd at 71 mph. "note the rev limit in 3, 4, 5, 6 is 6500 rpm"
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Old Nov 17, 2011 | 01:14 PM
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Originally Posted by madmax4499
hmmm, I dont know! were you scared to red line it? in sport mode mine will shift into second at 65 mph then rev to 6600 rpm and shift into third at 76 mph. try it again and hold it on the wood till it shifts. in D mode it will shift into 3rd at 71 mph. "note the rev limit in 3, 4, 5, 6 is 6500 rpm"
Just doing the numbers...
If you have the 2.56 rear gear, then the shift points at 6500 RPM would be...
1st---50 MPH
2nd---90 MPH
3rd--132 MPH
4th--176 MPH

If you have the 2.73 rear gear, shifting at 6500 RPM...
1st---47 MPH
2nd---80 MPH
3rd--124 MPH
4th--165 MPH.
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Old Nov 22, 2011 | 02:14 PM
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Originally Posted by madmax4499
hmmm, I dont know! were you scared to red line it? in sport mode mine will shift into second at 65 mph then rev to 6600 rpm and shift into third at 76 mph. try it again and hold it on the wood till it shifts. in D mode it will shift into 3rd at 71 mph. "note the rev limit in 3, 4, 5, 6 is 6500 rpm"
You must have a lower rear end ratio, but maybe you are right - I didn't want to red line it - 5500 in second is enough for me. I guess that I am surprised that it would not choose to shift into 3rd well before the red line at 6500. I have not looked at the torque curves, but I think that the curve should be pretty flat at that point and that the optimal shift point would be 4500 rpm or so (?)
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Old Nov 22, 2011 | 02:35 PM
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yes i pulled the numbers from the ECM with efi live. stuff happens too fast to be looking and writing it down, LOL

i cant give you a big detailed note about HP and TQ vs. shift points. it is in my head but i cant articulate it.

your right the engine will be in the fat part of the tq curve at 4500 rpm, but it will bog down if you try to short shift it.

so my point is if your trying to go from point A to point B as quickly as possible. letting the computer shift for you will get you there first every time.

any yes it will spin the tires at 70 mph on a cold road.

my advise to you is to enjoy your car! but seriously! try it! floor it at 60-65 mph and hold on! "dry road"
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