I also have some more valvetrain noise on my Sebring convertible with the 2.5 motor using Mobil 1 HM 10w-30. It used to be just at start up for a minute or so. Not it is on and off.
2002 Buick Regal GS (3.8 Supercharged) PP, Pure 1 filter
2008 Sebring Hardtop convertible (2.7) PP, MC filter.