Sounds like tank after oil change

[spugeddy]

After one year of ownership, I finally did an oil change with the correct oil.
I have been using Mobil 1 synthetic 5W-30. I know now that is wrong.

However, the car ran great, no oil leaks, no burn, no issues.

I put in Rotella Synthetic 5W-40 this weekend, and it now sounds like a tank. Very deep and loud engine noise, noticiable in the cabin.

It gets al little better when I hit the go pedal, but at idle, man it is loud.

Any ideas what is causing this....