Don't get too concerned unecessarily. The fuel injectors can make a ticking noise as they fire, especially on older cars. This doesn't necessarily mean its BAD. Just old, or dirty. You need to determine WHERE it is coming from. If it sounds like a click it's probably the injectors. If it sounds like a tap, it could be a valve or something more serious. Sorry, I do realize that on the internet it's impossible to describe the difference between a click and a tap!