Todior Loci

Hi all! I have An 2001 s430 with 152.xxx miles. Lately it has a ticking noise at startup only when it's cold out. It's there for about a min then it goes away. I change the oil every 5000 miles with Mobil 1 0w-40. This time I used liqui moly 5w-40 229.5 spec, the noise is still there, what could it be? There is no loss of power.prior 2 years the car sat for 3 months in the winter each year.