Ticking Noise

Recently Purchased A 2003 Trailblazer, And Since The Day We Drove It Off Of The Lot It Has Had A Very Loud Ticking Noise Coming From Under The Hood.( Mostly Does It When It Is Idling.) Have Had It In The Shop 3 Times, And They Say Thay Have No Idea What It Is. Anybody Have Any Ideas? Thanks!

Recently Purchased A 2003 Trailblazer, And Since The Day We Drove It Off Of The Lot It Has Had A Very Loud Ticking Noise Coming From Under The Hood.( Mostly Does It When It Is Idling.) Have Had It In The Shop 3 Times, And They Say Thay Have No Idea What It Is. Anybody Have Any Ideas? Thanks!

Is it only at start up, or happening all the time...?

I hope is not too late to help you. The ticking noise is from the fan clutch. Is located right in front of the motor fan. Keep an eye on your temp gauge, with time it will start going up until it could be a major problem (overheating). Its easy to replace it but it cost about $270.
good luck!