MiMitch

it can be felt and heard, its subtle, but its more than just the instrument cluster.

i'll dig threw the service records and see what i can find on fluid replacements / levels. i got lucky, the car came with a complete history in a folder

Mister Bally

If the engine is not actually varying in RPM's (You'll need calibrated ears to detect) then your crankshaft position sensor could be on its way out. I noticed this a few weeks prior to when mine went bad resulting in a no-start condition with the engine hot. My variance was much less though. About 200 RPM's at most.

MiMitch

the rpm change can be felt and heard, its not put ya back in the seat noticeable, but its pretty easy to notice.

Mister Bally

Sounds like a vacuum hose leak. Visual and standard automotive troubleshooting techniques come in handy for this.

Jack88

I remember when it did it the first time when I drove it, and it was at low speed, around 25-30mph. The change in engine rpm was audible.

MiMitch

i literally spit coffee..... i feel like this is the "heres your sign" response for this forum and it makes me smile, even when i get it.

MP4.2+6.0

Yet another thread BTW where it was harder to follow and participate in using linear mode, so just remembering a few things here as I respond:

Yes, as Misha first flagged, could be torque converter lock up. In turn, fluid check or even drain/refill might help. Could also simply try running a fresh tranny module (TCM/TCU) adaptation via VCDS to have it "relearn" shifting. From doing it once or twice now, adaptation can smooth things out in a meaningful way you wouldn't expect.

Mister Bally might also be on to something about a vacuum leak, particularly at a heat sensitive part/joint. Something like the combi valves (EGR side post warm up; pre warm up is air pump side) could be in play here too. But, I would expect the always (not) fun codes lean type codes if combi valves or vacuum is flaking. Or for another twist, something in the multistage intake system, though the first to second stage cut over point is supposed to be a lot higher RPM wise than OP is noting.

MiMitch

I'll Do this one tonight and let you know what happens, thans

MP4.2+6.0

First you trigger the adaptation via VCDS. Then you do a driving cycle that takes about half an hour with some quiet roads (night is good!). It is laid out at the end of the "hoot" tranny TSB.

On mine, only right near the end of the 30 minutes was it becoming apparent to me it was smoothing out (post a fluld change I did and ultimately solenoid and a seal change out) and not just wishful thinking. It did take a seal and solenoid deep dive change out to resolve mine, and then on adaptation drive it went from still not right feeling at start to right there right now, shift like no tomorrow forever new car feel post adaptation. I think dealers may not do the adaptation by the book or kind of short cut it, but pre and post I could feel a real difference when I ran into the other issues.

mattsimis

Yes Linear mode sucks.. but you can choose one of the other modes at any time..