Valve clearences (ohv), bad valves, timing out, bad rocker arms, piston slap.
Easy tests for all of the above, just Google them.
Some cars just have an annoying tick, only way to fix them is a good radio or cd player
depends on the car. may want to bring it to a car shop just in case (not likely to be a bomb)
the pullee to any belt could be bent
A ticking or clicking sound is probably lifter noise, the valves need adjusting
you may have a bent valve
You have an old car or it's about to be broken.
Is it a lifter ticking?
Starter motor, Flat battery or bad earth cables are the prime suspects
that would be the car indicator signal! that tells other drivers which direction your turning!
Diff whine
Could be stone in tyre
most likely a faulty relay
Could be a bomb but cant be sure without looking at it