Accent engine rattle on cold start
 

This seems like a silly question, but is it normal for a 2001 Accent's
engine to give a rattling sound on a cold start? I had not noticed this
before because I normally have my window up when I start. Basically, if I
start the car after it has been sitting overnight, the engine idles with a
rattling sound for half a minute or so. It fades soon after, and will not
recur until the car has been shut down for a long time. Googling on this
issue pulls up a whole bunch of possibilities for a whole bunch of cars, but
for some cars, this is supposed to be normal. Is it?

Thanks.

Chris