What happened white smoke from tailpipe stopped after few days sweet smell no engine problems coolant oil levels fine white smoke lasted a week spark splugs maybe 185000miles never changed them?

Answer 1

At some point coolant was getting into a cylinder. The sweet smell is antifreeze. The hole, probably in a head gasket was small enough that particles in the cooling system plugged it or as the motor heated up the head expanded enough to seal the hole. Doubtful this will last. At some point it should start smoking again. I have had good luck with copper based sealant when the coolant is going out the exhaust. If the radiator is being pressurized by exhaust then this will not help.