It depends; where is the sound coming from?
-Dashboard
When the indicator is engaged it will make a clicking sounds as the wheel is turned. This is normal, it is the mechanism used to automatically switch off the indicator when the turn is complete. Could also indicate a problem with air-conditioning, tachometer or speedometer operation or any of the other moving parts back there. Could just be a leaf or twig stuck in the air system intake.
-Wheels
-When turning
Could be either a suspension problem or an issue with the rim of the wheels. Should be checked out quickly as it is a problem that could cause handling problems in an emergency.
-Driving straight
Could have the same causes as above but could also be caused by a loose item in the wheel arches.
-Under car
Could be an issue with any of the running gear such as drive shaft or anything else that moves under the car.
Whatever the cause, mention the clicking next time you get the car serviced, it could just be a loose wire hitting something which would cost nothing to fix. If it is something that could be more dangerous then you would feel happy to spend the money to get it fixed. Or so I assume.
The car won't start but it is clicking
It's your car cooling down.....
When you drive over a clicking bettle.
It is low on freon.
A loud clicking sound coming from the front of your car when you are driving straight would be the result of a bad CV joint. This is something that should be checked out right away.
Ensure jumper cables have good connection
It's moderately loud, making clicking sounds when moving the loading mechanism, and sort of a "chuck" sound when shot.
If your car makes a clicking sound when you try to start it, try to jump the battery. If that starts it, check the electrical system and if it was the battery, replace the battery. If jumping it does not fix it, have a mechanic look at it.
A clicking sound when you try to start the car is a dead battery. It may be that the alternator is not charging it properly.
A bad starter
it's probably the head gaskets.
Depends on what's wrong with the starter, exactly. It could be whirring sound, a clicking sound, no sound at all, etc.