Engine coughs after start up...
 

This is probably a long shot, but maybe this will ring a bell with someone. My 2000S runs great, but lately I've noticed that when I start it when the engine is cold, after the valve train noise subsides, maybe a second later, it stumbles and coughs a bit... and then runs fine. Any thoughts? It's not a problem, but perhaps this is an early indicator. Appreciate any help or ideas.