just purchased 98 C230. Front right wheel area groans when going through a puddle.
 

I just noticed this the other day on my wifes car. It poured over the weekend, of course, and when i went through some puddles there would be a groan coming from the front right. It would last about 20 seconds until I went through another puddle. Any idea what this could be? I was thinking water getting a cv joint, if there is one on the front of the car. I have yet to crawl under this car since getting it in December so I don't know what the front suspension looks like. ????? Actually i did crawl under to change the oil and realized the cannister was on the top. ;)

sounds like you might need new ball joints

Why would you think ball joints. Wouldn't the groan be from something that is moving, like a wheel, and causing some friction. I will jack up the car and check the play in the wheel, but does a worn ball joint make noise?

That is the same problem I encountered with my old 300e. Each time after driving in the rain the car would squeak and groan. I temporarily fixed it by spraying wd40 in the area I thought the squeaking was comming from. This worked, until it rained again. It turned out to be that the ball joints were stiff,and I needed new ones. I greased the old ones up really good and after that it was trouble free.

Do the ball joints in these cars take grease or are they permanently sealed? If they are sealed then how did you grease them?

I am not sure about them being permanently sealed. I just sprayed wd-40 directly on the ball joints. It soaked into the metal and the squeaking and groaning stopped.