Rep Power: 0

I have a 98 civic lx and the oil keeps disappearing at random times. Sometimes i can go a week and keep the same oil level sometimes i will have to add a half quart every other day i have replaced the oil pan gasket, the rear main seal, the valve cover gaskets, distributor gasket, and intake manifold gasket and im just stumped now cause i put cardboard under it every night and it dont leak it and it dont burn it

 
Rep Power: 126

Is it safe to assume then that it's leaking only when it runs?

Is it leaking more toward the driver's side? There are a bunch of seals that you didn't mention near the timing cover area that could be leaking.

Did you replace the gaskets yourself? Are you sure none of them pinched without you noticing?

 
Rep Power: 211

Check the oil pressure with a guage. I owned a 2007 Mazda 3 that had a (Ford) 2.3L engine in it. Around 140k miles it started eating oil, no external leaks, no oil plumes or smell of oil from tailpipe. Oil consumption worsened pretty quickly and within a few months it was going through a quart about every two weeks. Internet research pointed to engine tolerances opening up (crank/bearing) to a point of permanent failure. Hopefully that is not what you're dealing with.

Other possibility is a smalll external leak that is burning off on the exhaust manifold or engine and doesn't leak to ground.
Check inside the distributor for oil and the distributor's external o-ring for leaks. Cam and crank seals are also a possibility.
Replace the PCV valve if it doesn't rattle when shaking it.
Remove and check spark plugs for oil. Buy a wire camera (connects to phone) to look for oil unwanted oil in cylinders.

Mazda 2.3L oil loss issues: https://www.google.com/search?sxsrf=...ile-gws-wiz-hp