I would agree with Mike regarding used engines. I assume this MBZ has some miles on the clock, I would do at the minimum, a complete valve job, not just replace the head gasket. Your are lucky it is not a V-8

I would have a good mechanic check out the bottom end too. Under normal conditions the blocks will last for a long time. (Unlike cast iron), aluminum does not tolerate overheating. Not to mention the possible bearing damage. Best of luck. (Don't loan your sister any more of your cars!!)

__________________
1994 E320 Cabriolet
1992 300CE (Sold)
1991 300SE (Sold)
1986 560SEL (Sold)