Recently purchased a 2007 durango with 4.7 and 4x4. At startup there is a ticking sound which mimics a bad lifter. As this is a overhead cam design engine what could be causing the noise. Lasts about 30 secs. then sounds fine. Googling this produces many complaints regarding this issue but nobody has the definitive solution. Anyone experience this? Also want to do my own oil changes, what oil and filter would you recommend, synthetic?? Vehicle has 98000 kilometers or about 60000 miles on it.