It could be a sticking hydraulic lifter or valves that are slightly out of adjustment.
battery is dead
yes, my 2000 grand prix gtp is losing power and makes ticking noise.
Most likely the ticking you are hearing is that from your solonoid. This is generally related with insufficient power from the battery.
Oil slow getting to the head
It is a 2002 Honda civic
Sounds to me like HOT exhaust cooling down.
possibly you need a better grade of gas?
It could be that hydraulic lash-adjusters may be clogged up.
The cool water hitting your piping hot exhaust makes the metal contract (Shrink) and it makes a ticking noise.
when i turn on the ac in my 2000 honda civic it makes a loud noise when the fan is working what could that be ?
The ticking noise could be worn out rocker arms under valve covers. Switch to heavier weight oil if ticking noise subsides that could be your problem. This is usually a sign of a high mileage engine. Worst case scenario would be weak oil pump not getting oil to top of heads.
the ticking noise is a small exhaust leak close to the exhaust headers or exhaust pipe near the engine.