clunking noise when starting?

[SpaceGoat]

After my car sits for overnight, it seems like it has a hard time starting. After i get it started I hear a semi-load clunking noise from under the hood. Its only usually one clunk but this just started happening. And if i dont allow time for the engine to heat up, it takes longer to "pick-up" after pressing the gas. What could it be and should i be concerned?

Thanks

 

[582Boat]

Engine Noise

My 85 Vette made a noise upon first starting up, sounded like a rattle nocking noise, then in a few minutes would stop. Answer for me was to remove the flywheel cover and tighened up the three bolts between the flywheel and converter. Doc