Swapped to synthetic oil in my old 7.3 and she's quiet as a mouse now

Threw in some Rotella T6 last weekend after years of running conventional and the valve train chatter is almost gone. Anyone else notice a big difference switching oils on an older motor?

2 comments

2 Comments

mila_reed7d ago

Yeah that "changed the whole personality of the motor" part really hits home... I read somewhere that synthetic flows way better when cold too so it gets to the top end faster. Makes sense for those old 7.3s that take forever to build oil pressure on a winter morning.

the_kai8d ago

Had a buddy with a 7.3 in an old F-350 who swore by conventional 15w-40 for years. Said it was all that old motor knew. Finally tried T6 after his oil pan gasket started leaking and figured he might as well while he had it apart. Called me up the next day all excited cause his truck actually idled smooth for the first time in ten years, like the oil quieted down some injector rattle he thought was just normal. Funny how something simple can change the whole personality of a motor.