I started the Hemi R/T the other morning, I quess about 75 degrees and it sounded like an old Ford motor with a lifter clattering for a couple seconds till oil reached it. I have about 9500 miles on the car. The car did sit for 3 days not being started. This has never happened before and hasn't happened since. What do you think happened? Has this happened to any of you guys? I am now thinking of going to 5W30 oil. I am in South Louisiana and the temp rarely ever drops below 40 degrees in the winter. I bet I could get away with heavier oil. The 5W20 is like water! I don't like that,can't provide much protection. What do y'all think?