Engine hard start
 

I have a 190d, m601 engine 4 cylinder. My car has no fan shroud and typically goes to slightly over 80 degrees in congested roads. If i turn it off at that temperature it makes a hard start and sometimes wont start. It only starts after a while and has cooled. History: once cracked sump, crankshaft was reworked, bearing replaced. Head gasket was also replaced after removing head for a routine inspection. Any ideas on what would be the root cause with the hard start problem.