Ticking noise when accelerating

I am not a great fan of flushing transmissions using a flushing machine but definite encourage you to change the transmission oil at least every 30,000 miles and remove the transmission pan to change the transmission oil filter. Your engine has hydraulic lifters to adjust the valves automatically perhaps a lifter is dirty or has restricted passages ways that cause a noise until the oil gets hot and "thins out". There is also a possibility that the noise is exhaust related perhaps a small crack in the exhaust manifold that once the engine reaches operating temperature the noise would go away when the manifold expands with heat. Hard to guess with out hearing the noise first hand.