Thanks for the tip. I might try that. What I really need to do is get the car into the mechanic I use that I trust and have him do a block test. I've been putting off doing that because the dealer said I needed a head gasket and a valve job and he gave me a price of $3,500. This was 2 years ago so I am sure they would charge me more now.

After reading the replies here it really does not sound like I need a head gasket. I don't have any oil floating around in the overflow tank and my engine oil is clean. I've been told if water was in there there would be a white color mixed in with the oil. Nothing like that is on my dip stick. I've been looking for a Mercedes board for awhile. I found a Miata board last year and discussed my problem with the guys on there and they said that the Mazda dealer was full of crap. It appers that the Mercedes dealer might be full of the same thing! I think some of these dealers know that a lot of women don't know a thing about their car. Which in my case, is true.