What could be the problem with this 06 charger

Are you running Penzoil motor oil?

First off pennzoil is great oil. It's absurd to believe it causes sludge. And pennzoil,quaker state,shell are all made by pennzoil. So get that idea out of your head. Im running 10000 mile intervals on pennzoil and no deposits whatsoever in my hemi. If there's heavy sludge I suggest going a grade thicker and use an engine flush type product and shorten the interval to 2000 miles until clean. If there is heavy deposits you want it to clean slowly to prevent any chunks from coming loose and potentially blocking the oil pick up tube. Seafoam type products work great in these situations.