Oil consumption

Hondaracer315 · May 1, 2014

Quick question about 7.3 oil consumption. 02 7.3, during the winter I use 5w40 Rotella T6 and she will use about two quarts every 4000 miles. But in the summer I use 15w40 and I don't use a drop. Why is that? Thanks.

Pwnm30rdi3 · May 2, 2014

I remember reading in a ford owners manual that 1 quart of oil consumption every 3,000 miles was acceptable.
I would find 2 quarts normal for a higher mileage motor with 4,000 mile oil change intervals.

Hondaracer315 · May 2, 2014

Thanks.

DEEZUZ · May 2, 2014

Most of it will be seeping past turbo seals. I remember Subaru stopping the use of thin synthetics due to this very issue.

I'd worry more about the mixing of the weight and airetion your causing... Stick to one weight

Hondaracer315 · May 2, 2014

I need to use the 5 weight in the winter because I am in AK. I have started the truck unplugged in -20 -30 weather because where I work there are no plugins. Now for the mixing issue. Mixing those two oils has no ill effect on the truck at all because they are still using the 40 weight. The 5 weight is for the start up why, because we have to utilize the heui system. And this is where oil is taken through the high pressure oil pump to power the injectors. Trust me I researched the crap out of this before I made the switch back and forth. Oh yeah by the way it's recommended by a lot of the big time trucking companies up here that you do switch during the winter. Also the turbo was completely rebuilt 2 years ago so it is not my seals. The heavier the oil the harder it is to start, also I think the manual states to use 10w30 below what 30 degrees or something like that? Thanks.

DEEZUZ · May 2, 2014

ghohouston · May 2, 2014

If you're burning 5w40, then I'd switch back to 15w40 and not worry about it. Are you sure injector o rings aren't gone?

Hondaracer315 · May 3, 2014

Yeah the injectors are new with new injector o rings. I think I might have some piston ring seepage.

ghohouston · May 3, 2014

Does it have a lot of blowby?

ToMang07 · May 3, 2014

Hondaracer315 said:
Yeah the injectors are new with new injector o rings. I think I might have some piston ring seepage.

What about the turbo/EBPV/Pedestal area? Any leakage?

dmd · May 3, 2014

Mine will use more with rotella than delo. Rotella will use two or more quarts in 5000. Delo it will use one. Same weight.

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Hondaracer315 · May 3, 2014

No pedestal seepage I deleted my pedestal arm and put a freeze plug in it. There is no ebpv either I have the banks down pipe off the turbo. There is no blow by either. I put the cap on the filler tube upside down and it just sits there. But my compression in 3&5 cyls is about 390 all rest are 420PSI.

Arisley · May 3, 2014

Hondaracer315 said:
Yeah the injectors are new with new injector o rings. I think I might have some piston ring seepage.

Hondaracer315 said:
No pedestal seepage I deleted my pedestal arm and put a freeze plug in it. There is no ebpv either I have the banks down pipe off the turbo. There is no blow by either. I put the cap on the filler tube upside down and it just sits there. But my compression in 3&5 cyls is about 390 all rest are 420PSI.

If you have no blowby, you have no ring "seepage". Leaking rings allows combustion gases into the crankcase. That is the definition of blowby.

With the thinner oil, it gets consumed faster, more is left on the cylinder walls, and when it goes boom, it burns up with the diesel and the air. It is a microscopic amount on each detonation, but there are a lot of detonations happening.