White smoke is an indicator of in burnt fuel or engine oil leaking into the combustion chamber. With the sound It’s’s making, I’m thinking you have low compression. That could be why your getting white smoke and harder than normal startup. The rod bearings could be an issue, causing the pistons...
Get ready. My 15 did the same at 20K miles. They tried to “repair by replacing bottom end. Ran like a slug. I found out they dry fired the engine on restart. Scored the injectors. (No wonder it ran so poorly). Engine gave it up again. This time upper end. ( oil dilution from pissing injectors)...