"I own a 2008 F150 with a 5.4L Triton, They are known to have that dreaded "cam phaser" sound. Ever since I bought it and changed my own oil I have used Lucas Oil Stabilizer and had hardly any of that "dieseling" sound. But recently I had the oil changed for free of charge at teh dealer and they of course didnt put an Lucas product in and I swore it was making a louder than normal sound from the engine. So I carefully drained off a qt of oil and replaced it with Lucas Oil Stabilizer and almost immediately the sound went away and sounded like she always has. So I guess that will be my routine now after I get my free oil changes at eh dealer. Thanks for making such a kick ass product!!!" -Scot Shamet