I have a 2006 Dodge Hemi 1500 Mega Cab. The manual says use 5-20 oil. It has had lifter noise since new when cold and at idle. Used 0/20 Mobil 1 & Wix filter, 5/30 Amsoil & Amsoil EOA Filter, and now 0-40 Mobil with Wix Filter and nothing helps. It has about 22,000 miles and is still under warrenty. Hate to have a dealer tear into it but I do want to fix the noise. My son has an 06 Hemi and no problems. Any thoughts? Thanks!