parker_hall5•14d agoMost Upvoted

Switched to synthetic oil after seeing the internals of a 7.3 Powerstroke

A buddy tore down his '02 Ford with 250k miles on conventional oil and the sludge was bad. I looked at a similar motor that ran synthetic its whole life and the difference in the valvetrain was night and day. Anyone else see enough proof to make the switch?

3 comments

3 Comments

sagejackson14d ago

I had a buddy with a '97 F-250 who swore by conventional oil and did 5k mile changes like clockwork. He pulled the valve covers at 180k and it looked like someone poured tar in there... rockers had this thick crust on them. Meanwhile my neighbor's '99 7.3 with 220k on synthetic was clean enough you could eat off the pushrods. That was enough proof for me, I switched all my stuff over after that.

pat_harris14d ago

Man that's a hell of a difference right there. @sagejackson what kind of synthetic was your neighbor running? My dad's old 94 7.3 has been on Rotella T6 the last 60k miles after 150k on dino oil, and I'm curious if any brand makes a bigger difference or if just switching to any synthetic is the main thing. Always heard the 7.3s love the high zinc content but some synthetics don't have as much as the conventional oils used to. Wondering if your buddy's truck just needed a quality conventional or if synthetics really do keep the sludge away that much better over the long haul.

the_daniel14d ago

@pat_harris yeah you're bringing up something a lot of folks miss. Those old 7.3s really do need that zinc for the flat tappet cam, and some of the newer synthetics have lower levels cause of emission stuff. But here's the thing - it's not just about the oil brand, it's about the change interval too. Your dad's truck with 150k on dino oil then switching to Rotella T6 for the last 60k, that's actually pretty smart cause the synthetic will slowly clean out some of that old varnish over time. But if it already had sludge building up, don't expect it to be spotless overnight. That cleaning process can actually clog up oil passages if it happens too fast, so you gotta be careful. I've seen guys switch too late and the synthetic loosened chunks of carbon that killed the turbo. So honestly, the difference your buddy saw between those two motors was probably a combo of synthetic AND better change habits over the whole life.