Toyota Corolla 2002 Burning oil

Trying to find out where the oil is going, had a whole exhaust and cat replaced, oil change, replaced the oil cap. Trying to find if there is a leak I don’t see any oil near the engine except where the cap is. Any one know what could be burning my oil? At the end of a week and half I usually have to fill it up almost entirely.

Another thing is when I check the fill area there is some black sludge looks like dried up oil. Not sure if that is a concern or not.

If it’s not leaking oil then it’s burning it past the piston rings or valve seals; probably the former.

A compression and/or leakdown test may reveal a ring problem. Generally speaking, oil loss past the rings is caused by oil control rings that are coked up; meaning they’re stuck due to burnt oil.
That dried black sludge you refer to could also be the same thing affecting the rings.

An additive such as SeaFoam, Berryman B-12, etc, etc. added to the engine oil may, or may not, help ease a problem like this.

I believe this engine was known to sludge up if the oil wasn’t changed frequently

And I also believe this engine had a history of oil consumption, due to stuck oil control rings

Take off the valve cover and look for sludge

Take out the plugs . . . are they oil fouled?

How much oil? Miles per quart?

How much oil is it burning? If it’s a quart between oil changes then I would forget about it since that well within normal. If it’s more…check your owner’s manual. You may be able to go up one weight and that may slow the oil burning process. I’ve have real good success with doing that. Just remember that if you live in a hot or temperate part of the country…you don’t need “thin” oil that’s needed for winter driving.

Look at the area around the front of the engine, down low where the crankshaft pulley is. Look at the surrounding area for signs of oil on the shields and body areas. This would indicate a leak of the front seal where the oil hits the pulley and is slung into the surrounding areas. This is common on this engine and is an easy fix.

Rollen, first we need to know how many miles the car has on it and also how many miles you drive before you need to add a quart.
You said “At the end of a week and half I usually have to fill it up almost entirely”, but that doesn’t tell us whether you’re just adding a quart or four quarts. Nor do we know how many miles you drive in a week and a half.

If the car has 250,000 miles on it and you’re only adding a quart every 1,000 miles, you may not have a problem at all. But you need to tell us.

I can tell you that if you changed the exhaust system, including the cat converter, and the oil cap all in the quest to reduce oil usage, you’ve already spent a lot of money on things that do not cause oil usage. I recommend strongly that you do nothing else until you find out if the amount you’re using is normal (post the requested info) and/or get some ideas as to the cause of the oil usage (if it’s abnormal). Otherwise we’re all just wildly guessing and you’re just spending money for nothing.

I can’t really comment on where the oil is going, but if you’re letting the oil drop four quarts or so (“have to fill it up almost entirely”) your engine is likely wearing out very quickly. Check the oil and top up every day for a while until you get the oil loss figured out.

Oil burning is a pattern failure for this engine. It is the piston rings.

Running it chronically almost out of oil means it’s on the last mile.

The new converter is not going to be long for this world either at that oil consumption rate.

I agree with your comments guys, but I’m still not sure that’s what the OP was trying to tell us. I’ve reread the post, and it just doesn’t seem clear to me.

OP, it would be great of you could post and answer some of my queries. All of us here would really like to help.

Good comments above, esp that changing out the cat with this problem remaining unresolved may prove problematic. While the ultimate cause sounds like a piston ring problem, I’d advise you have the PCV checked next time you visit your shop.