plastic fan blades/body cracked over time. Eventually the fast spinning while engine is running caused a fatal fatigue of the parts. There are posts here from time to time about it happening to others...
Bad PCVs are one known cause of the dipstick issue you mentioned. Try changing them and see what happens? Also probably a good idea to replace the PCV hoses too. If engine is good otherwise (ie., good compression, no smoking, etc) -- no reason to replace it...