We were all wrong! I started looking for the pressure sensor, couldnt find it, so moved on to try to put another can of 134 in it. After a little went in, I noticed a high pitched hissing. Seems my problem is a leak in the condensor. (which i do believe was the easiest part to remove on the entire car!) So, I'll see if that is fixable or if I can find a new one. then I guess I'll need oil, 134 and guages. Any idea how much should go in?
thanks again for your help,

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Paul
2004 E500 4matic; 72,000mi