Thick oil causing low oil pressure?

[thunderstruck]

Sounds like all the oil is being pumped up to the heads, and taking it's sweet time to drain back through the likely half plugged oil return holes in the cylinder heads and the pump is starving for oil. High RPM + thick oil + slow draining back to the pan can certainly cause this.

Yup. Heard about this happening with a lot of older Dodge V8s.

With that said, what is with the obsession of running heavy oil in these gas trucks?? It's not like we're running air-cooled shared-sump engines.


Sent from my Nintendo 64

 

[98_k1500]

I have a 55 gallon drum of it...

 

[21Actual]

I second the ATF flush. I do it every 3rd oil change. 100 KMs before an oil change, Drain a quart of oil, replace with ATF. Cleans up the internals quite nicely. Change my oil every 5000KMs religiously, usually still somewhat golden, never black.

Strange though that your oil pres issue is happening only with the 10-40. Theirs something else going on. Heavier oil will bump pressure up a bit, not drop it.

Either way, get those lower intake gaskets done. Sounds like a nasty leak.

 

[joedee]

What do you recommend to use to flush it?
I was planning on running some Seafoam through it, is there anything else?

b-12 chem tool maybe seems pretty good ..thats about it man most really good engine flushes went away in the early 1990's

 

[joedee]

Yup. Heard about this happening with a lot of older Dodge V8s.

With that said, what is with the obsession of running heavy oil in these gas trucks?? It's not like we're running air-cooled shared-sump engines.


Sent from my Nintendo 64

Well that is true about heavy oils . I grew up in an performance shop all my life and continue to work in one today and It's a habit of being on hand instead of feeding the local wal/napa/zone/advanced blah blah auto parts store mart .royal purple , kendal or valvoline always here on hand . Or it could be cause Drove a 348 chevy and 406 ford until I was in my late 20's ..