Oil goes missing....

[MiXdNuTs]

My 94 learner sentra is eating oil. It started doing this abruptly a while back and there has been no change in how it drives or mileage. The exhaust is never smoky.
It does leak oil, but only a little. I replaced the valve cover gasket a while back to try to fix that.
I have to add a few quarts every other tank of gas.

I want to know how I am loosing all of this oil. It is certainly not all on my garage floor. There are only a few drops there...
I can't figure it out.

[slideways...]

theres something missing in this story...either your burning or leaking. if its not in your coolant.
oil doesnt just disappear. most likely you have leaks that happen while driving. your cars oiling system is pressurized, so when your engine is running under load it has the potential to leak the most.

[MiXdNuTs]

I have not checked my coolant. I will do that tonight when I get home. I don't think my oil system should be pressurized because I recently replaced the PCV valve.
However, a leak that happens most when the car runs does sound very likely here. I will have to try and run my car with cardboard under it and see if it leaks alot more than the usual 1 - 2 drops a night.

Could the oil pressure management system that feeds into the intake be backed up somewhere else? It makes sense to me because I had a blown out valve cover gasket a while back and that may have been related to too much pressure. I believe it is supposed to actually run a slight vaccume under the valve cover.

[fugiot]

What he meant is that your oil is pressurized when the car is running. All cars have oil pressure when the car is on.

I''ll bet it's just an old oil pan gasket that doesn't leak too much unless the car is running.

[slideways...]

Originally Posted by MiXdNuTs

Could the oil pressure management system that feeds into the intake be backed up somewhere else? It makes sense to me because I had a blown out valve cover gasket a while back and that may have been related to too much pressure. I believe it is supposed to actually run a slight vaccume under the valve cover.

im not really sure what your asking...theres oil pressure in the oiling system, but the valvetrain really only gets misted by oil coming from the passages thru the block. there is supposed to be slightly higher pressure in the valve covers because the pcv valve lets air in but not really out. the valve cover gasket is only designed to prevent water or dirt from entering and oil from leaving the engine. it doesnt hold pressure like a headgasket does. but that doesnt have to do with your problem. the reason i told you to check your coolant for oil(hint:coolant is water based so oil will separate like in water) is in case of a cracked head or blown head gasket. im 99% sure though that you have external leaks and thats all.

[MiXdNuTs]

Slideways, I just got back from my seeing my mechanic (finally) and it is a leaking oil pan gasket. The coolant is fine. Thanks for all of your input.

Also, the PCV lets pressure OUT of the valve cover and into the intake so that the noxious fumes that leak from the valves are consumed in the combustion chambers. Instead of a PCV valve, old cares used to simply run a hose to the bottom of the car where it vented the fumes and polluted the environment. If it didn't let some of this pressure out it would build up so high that it would blow out all of your seals, which is what happens when your PCV valve is clogged due to missed oil changes.