Mercedes: popping noise in drive train, mercedes benz 190e, sway bar link

Question
Noise level is constant but it gets faster as the speed increase.  It pops when chassis is compressed like you are going over a bump in any speed.  Sometimes it pops when you let off the throttle in a highway.  I'll check the bearing carrier and thank you for your prompt and knowledgable response.-------------------------
Followup To
Question -
I have 90 mercedes 190e w/ 2.6l auto.  When the car is making a turn it makes popping noise until you finish the turn.  It also pops when I carry any passengers.  I wiggle the drive shaft and both axles back and forth but not much play at all.  I checked the shock mount bolts too and they're tight.  Olny thing I've noticed was the flex disc was not flat but the bolts were tight,  and I don't know how to check the center bearing carrier.  Help!  Thanks.
Answer -
Does the popping noise follow vehicle speed and become louder on turns?

Possible bad wheel bearing.
Lift each wheel and wiggle = check run out = sloppy bearing.

A bearing failure is dangerous = can kill you or others.

Center drive shaft bearing carrier:
should be checked with , vehicle off, front wheels blocked, jack stands supporting rear of car, transmission in Neutral.
Inspect for wear, slop and rotate feeling for rough spots in bearing.

The flex disks need to be replaced if they are swelled, cracked or have the cords showing.

Answer
More to check:
Rear sway bar links = much noise when they go bad.

PART NUMBER SEARCH RESULTS WITH PRICES
Vehicle 1990 Mercedes Benz 190E 2.6
Part: Sway Bar Link

 Note:  Rear
From rear sway bar to trailing arm.     
L1030-16352 Sway Bar Link Febi IN STOCK $11.27  

http://catalog.eautopartscatalog.com/mercedesshop/sophio/wizard.jsp?partner=merc