When my car has been sitting for awhile and is cold it makes a "clunk" noise right under 2k rpm and then it goes away and the tranny is smooth. Took it to the dealer and they said it was the ABS pump? Doesn't sound like it to me...

 

The ABS check makes a very odd noise EVERYTIME you start your car and roll out. Mine happens about 10 seconds out of my driveway every morning.

If it only happens when the engine is cold, it's something else. For example. I start the car, drive to work. I get the clunk on the way down the block. I get to work, go inside, then have to run over to another building for something. I jump in the car (no longer cold) and start her up - as I drive away, I get the clunk.

Is yours the same, or ONLY when your engine is cold?

 

I think it is something else because when I got an 04 loaner car I never heard this sound at all. That is what concerns me.

 

I've had three A/T Infinitis lately, and none of them ever 'clunked'.

Your dealer may be wrong on that. Get another dealer's opinion.
C.

 

If it happens every time you start your car, only once after you start driving and go above about 5MPH, it could be the ABS self check but it's more like a boing sound. Kind of hard to explain the sound but here's my post:

https://g35driver.com/forums/g35-sedan-v35-2003-06/51274-boing-sound.html

It also has a link of another driver asking about the same thing. Hopefully it helps.