The most likely cause of a ticking sound in a motor is a bad timing belt. A valve out of time can also cause a ticking sound.

Please describe where the ticking is coming from, and what you're doing (if anything) when it happens. Please describe where the ticking is coming from, and what you're doing (if anything) when it happens.

turn your blinker of

The ticking could be just the pipes expanding and contracting. Or, the heating elements could have a build up that occurs over time.

i was told by a Chevy serviceman that the ticking noise was coming from the fuel injectors firing.but to me it sounded more like lifters tapping or floating.