Old timer at the parts counter said I was wasting money on synthetic oil for my 7.3

Guy named Jerry at the NAPA in Bakersfield told me I was throwing cash away running synthetic in my 7.3 Powerstroke. Said these old IDI engines were designed for conventional 15w40 and the seals would start leaking. I argued with him for like 10 minutes but he just shrugged. 6 months later my rear main seal is seeping oil on my driveway. Should have just listened to the guy. Anyone else had seals go funny after switching to synthetic?

2 comments

2 Comments

andrew719d ago

You sure that's a 7.3 Powerstroke and not the old 7.3 IDI?

brianellis18d ago

Hold up @andrew7, you really think that's an IDI? I'm looking at the glow plug controller and the injection pump placement. That valley pan and the turbo setup scream Powerstroke to me. The IDI had that mechanical pump on the side, not the high pressure oil system. Pretty sure the 93 model year is when they switched over too.