Well I Have A 04 Dually With 48000 On The Clock And I Am Experiencing The Same Thing. It May Be Because Of The New Usld Diesel Fuel Or Maybe The Winter Grade Fuel. Not Sure What Is Happening But Everything On My Truck Checks Out And No Problems. I Buy My Fuel At The Same Place Every Time So I Know It Is Not A Change In Fuel. Hhhmmmmmmmmmmmmmmmm....................?