yes do check that hose when sat overnight and also it should be checked when its running. When its running at operating temp the upper hose should be soft, if its stiff AVOID IT!! The temp SHOULD NOT BE AT THE 100*C mark when its idling or driven it should be at
80*C or a click above 80*C , why these OM603 should never run at 100*C, Well these aluminum head has a possibility to crack when it's driven or idling @ 100*C for some time, do some research, do these tests and do dont make a $3000 mistake that i made...

thx

__________________
Current Garage
2008 Mercedes GL320 CDI 188k mi Repair/Work in progress
1994 S350 160k mi Garage Queen & prepping for repairs
2005 E320 CDI 203k mi Healthy & Daily Driver
1994 S350 357k mi Retried as parts car
1984 300TD 214k mi Blown OM617 Poss OM603 Swap??

Sold
1987 300SDL 200K+
1994 S320 181K mi
2008 E320 Bluetec 127k mi
1999 S420 130K mi
1980 240D 360k mi
15+ Others that has come, stay and gone

GONE, BUT NOT FORGOTTEN
1995 E320 SE 220k mi
1984 300SD 350k mi