vmaddon

My CLK55 just turned 40k. On cold start, there is a noticeable groaning noise coming from the engine / transmission area. As the car runs for a few minutes, the noise gets less noticeable, but never leaves. I can best describe the noise as that from a weak comporessor or PS pump.

OK, must be a tensioner, pulley, or belt drive device.
To troubleshoot the source, I pulled the serp belt. How fun is that
Anyway, to my disappointment, the noise remained the same.

The only other source I can think of is the trans.

Now, I would suspect that a proper trans fluid / filter change would be the best place to start, especially since I expect that it is original.
But looking beyond that...

I have 2 questions.

1. Has anyone had a similar experience they wish to share??

2. How different ( expensive ) is the AMG CLK55 trans from the 430???

Any other suggestions appreciated as always.

Thank you

Vince