Something else to consider:

bad hose - cap still bad - bad expansion tank - t-stat issue.

http://db.mercedes.cx/mbsearch?words=collapsed+upper+hose&method=and&format=short&sort=score&config=fuzzy&restrict=mercedes&exclude=

__________________
Mike Murrell
1991 300-SEL - Model 126
M103 - SOHC
"Fräulein"