120k on the truck, has new and properly functioning pcv also plenum is fixed. takes half a quart every thousand miles. 15 year old truck i dont expect it to be perfect but is this normal for our 5.9's? no leaks on the ground or anywhere on the motor. thinking just tired rings maybe?

 

Did you look in the throttle body just to be sure the plenum didn't go again? Valve cover gasket maybe?

 

yes i have checked down the throttle body and it is still fine. i was thinking valve covers. once and a while on start up i can smell oil. not burning oil but the smell of new oil, like if you were to open a bottle and smell it haha. but never can i find a trail or pool of it.

 

Mines does the same thing. I can smell oil every once in a while when I start the truck. Mine leaks out if the rear main seal. If u get under the truck do u see oil coming out of the bell housing?

 

i thought the same thing especially since its an easy fix of just dropping the pan but its dry there.

 

To fix a rear main seal u gotta seperate the trans and motor from each other. I never noticed any puddles just a few drops on on the front if the bell housing. What does the inside of your exhaust look like. If u rub your finger in the end of your exhaust does it come out all black?. Also check your radiator make sure it's not going there. Check your timing cover also for oil coming out there. Bad cam seals will leak out there

 

coolant in the radiator is still perfect color. exhaust is not black timing cover is dry. bell housing is dry. is a half quart per thousand miles even a concern on something of this age?

 

My concern is that u don't know where it's goings. Its insettleing. Half a quart is kinda alot. A leaks I wouldn't worry about. As long as u check your oil. A plenum I'd get fixed. Blow by from bad rings I'd get fixed. If u can figure out where the oil is going then u can determine if it needs fixed or not. Oil just doesn't disappear. If it's 100% completely dry underneith then u need to look else where for a leak. Then determine if your compresson is good. Vaccume test compresson test then report back.

 

i did a compression test maybe 6000 miles ago and it came back with solid numbers. valve cover on passenger side is dirty and some what wet but it sure doesnt look bad enough to be the source of that much oil loss. i would say wet is an overstatement.

 

You can chalk a quart of oil every thousand miles as typical for a high mileage engine. I wouldn't really consider 120k high mileage. But half a quart is nothing to fret over.

Probably a combo of slightly leaking valve covers and valve seals. Valve seals get old from shear age. Especially if the truck sat for 5 years without moving a lot. As these old brutes are want to do.

As long as you got good power i wouldn't lose any sleep over it.