I recently found out as of today that if u live in a place where it gets over 100 degrees and u run pennzoil platinum 0w-20, do not run this weight in hot weather. it will crystalize. i had similar problem last summer, i thought it was a lack of changing oil. It was my first oil change on this car since i bought it and oil was badly crystalized. i upped my weight today to 5w -30. it still falls in specs for chrysler ms-6395 which this car calls for, gonna see if this helps. I am not sure about other oils but know for a fact in climates over 100 degrees do not run a 0 w 20 weight oil.