2.0L ('83-'88) Intense fumes from catalytic converter, absence of oil

[neinnein_nein]

After not having that problem at all, my 2.0 engine is mysteriously losing oil very fast and after warming up, it looks like thick fumes emanating from the cat.
I’m swapping a turbo coupe engine into it as soon as my new harness arrives in the mail (12 days from now?) but in the meantime, this is quite a PITA. I noticed the transmission case is smeared in oil, but there’s never really any significant oil deposit on the ground. I put two quarts yesterday, dipstick showed ok level, today there’s not a drop of oil on the stick.. Does it sound like a rear main seal that slowly failed and is now completely blown? It’s the first thing that came to mind..

 

[tomw]

Nothing on the ground, but lube is missing generally would indicate it is being fed to the combustion chamber. A clogged PCV can cause excessive consumption as can a gummed oil separator. Separator is mounted in a metal canister attached to the side of the engine, underneath the intake manifold. It has a large tube leading to the PCV valve(inline, near the dist) which continues on to the intake manifold. It can hoover out a lot of oil quickly.
tom

 

[Ramcharger90]

If that valve is clogged it could have blown out a seal also

 

[neinnein_nein]

i guess “somebody” forgot to check the oil for 2.5 months. running fine now and keeping the 3 and half quarts I added. PCv valve looks fine, i changed it about a year ago, still rattles and everything. I guess I’ll find out about the valve when I pull that engine in a week!

 

[Dirtman]

I didn't read this whole thing but i post this simply based on "the PCV valve still rattled".

The PCV valve cost a few bucks and literally determines how filthy your valves, intake, throttle body, etc get. It is the single most overlooked maintenance item ever. Rattling doesn't mean its good, if you took it off to check it REPLACE IT!

An improperly working PCV valve will shoot oil into the engine and fill it with carbon, or back up, fill the intake with oil making the throttle body gummed up. A million problems come from a 5 dollar part. Replace it...