I started my 2010 Scion XD early last week. I run 15w-40. On start up I hear this ticking! What! OMG! NO! I sit in the car listening as the 1.8 Toyota engine warms and the ticking is constant! I rev it a bit and the ticking is still steady. I roll the window down and then I feel shook STOOPID. I live next to a sod farm and my neighbor just built one of those rolling field irrigation systems. He set the timer to start watering that morning before sun up and it makes this steady ticking noise as the water pressure moves the giant wheels and watering apparatus! Whew!