Bad internal oil leak..

[skyline084]

92 NA 300zx
I am losing mass quantities of oil here... drove about ten miles, did some high revs , and about half a quart is gone.
Just finished rebuilding heads, only have 350 miles on the car since.
Did compression test, approx. 180 psi on all cylinders.
Attempted Leak down test but harbor freight tester is junk..

Possibilities?
Bad oil rings- wouldn't really affect the compression or leak down due to compression rings, correct?
Valve stem seals- Just replaced these so I don't see how they would be leaking already. Plus half a quart in ten miles is just crazy.

There is oil in the intake manifold plenum on both sides.
PCV valves were both replaced as well....

[nissanfreak12]

Did you test right after the 10 miles or did you wait at least an hour? I wouldn't be too alarmed, it still could be seeping down from the heads. If after an oil change, could be in the oil filter. Lot of possibilities, check after a few drives to see if any change.

[skyline084]

I did the compression test about half hour after running it, then again after the leakdown test.. two hours later or so.
It's def. burning oil though, coughs up some good smoke under revs..
Is there really that much oil surrounding the valve stems?? where half a quart could blow through in 10 miles?? I know 60psi is pretty good pressure, but it's just so much oil disappearing so fast haha it's just weird.. nothing is external either.

[t.mcginley.jr]

I know you said the heads are rebuilt, but how many miles are on the bottom end? what kind of head gaskets were installed? Did you do the rebuilding of the heads or a shop?

[skyline084]

I know you said the heads are rebuilt, but how many miles are on the bottom end? what kind of head gaskets were installed? Did you do the rebuilding of the heads or a shop?

Around 102 K miles on the bottom end. Good oil pressure though, crosshatch in cylinders still there. Doesn't look too worn.
I bent intake valves so only replaced the ones which were bent. I put everything together, but brought to a machine shop to have cleaned and pressure tested. I used Felpro headgaskets. I pressurized the cylinder and there wasn't any change in the radiator. I put a good amount of air in each cylinder and didn't hear any obvious leaks.... but the harbor freight leak down tester is junk.
Leaking valve seals wouldn't show up on any leakdown test anyway... so i'm guessing those are some how the culprit? even though they are brand new... maybe I didn't press them on enough .. even if they weren't, It's crazy that much oil is leaking into the cylinders.

[Mkiisupra]

How well did you seal the valve covers?

[skyline084]

Haven't had time to really tear this thing apart, but what could cause a quart of oil to be leaked into the cylinder besides bad stem seals. It's only on two cylinders too by the way.
If it were rings, why would only two be blown.. and would that much oil bypass every set of rings? Were talking a quart of oil burnt every 50 miles, maybe less.
Or could be a cracked block on those two cylinders.
It's not a headgasket issue because there is no sign of oil in the coolant, and no sign of coolant being burned through oil.
Anyone chime in?