I have a '92 Honda Civic EX with 156k miles. It runs fine and doesn't
give me any problems. The oil was changed about 500 miles back.

I hear this very fast ticking noise on about the first five blocks in
the morning. Then it stops. It's coming from the motor and some one
else probably wouldn't notice unless I pointed it out.

When I start the car, it idles at about 1500 RPMs. About three or so
minutes later, it is at around 1100 or 1000 around five minutes. Now
if I take off, I don't hear this noise. I imagine the noise is the
engine turning at higher RPMs because the oil has not heated up yet and
it takes more effort to turn the cam. Once the motor heats up,
everything is well lubricated, hot and so it runs very smooth. But
what could this noise be?

Also, do I actually need to wait until the car idles down to 1100 RPMs
each morning? I've read that about 30 seconds of warm up time is just
fine. My car is just below 1500 RPMs at 30 seconds. To me, that
doesn't show it has warmed up at all. What's the general concensus on
this?

Thanks,
Brett