76k on my Hemi and have always run full synhetic oil, changed it and used injector cleaner every 5k and only run top tier 89 octane, and the tick would never go away. New EGR helped but still made the noise. It is time for an oil change after 5k on Valvoline synpower, so I added 10 oz of Seafoam to the old oil. WIthin 15 miles of driving the tick is totally gone, and the MDS is so smooth you cannot even tell when it switches on and off. It seems the lifters in the Hemi get sticky after a while and the Seafoam loosens up deposits and frees them up. I'll drive it another 20 miles or so before changing the oil with Synpower, and can't wait to feel how smooth is runs !! I was a bit of a skeptic until today about Seafoam, but am sold on it now. Just don't use it on any older motor that has any oil leaks, or it will make them worse.