Oil consumption on Toyota w/o leak or smoke

Catalytic Converters often mask any visual smoking problems .

One among many possibles is if the water pump has ever gone out or other cooling system problems has occured resulting in gross overheating the piston rings might have taken a set . Your burning oil at a rate of a quart every 600 miles which is probably far more than any valve guide or valve guide seal problem could create .

Suggest running a compression/leakdown test on it and make certain the engine is not pinging which will destabilize the ring pack and wear the rings and ring lands because of the excess pressures .

BTW , few years ago I suggested to an internet friend to soak his sticking Saturn piston rings with Berrymans B12 overnight through the spark plug holes and it reduced his oil consumption by 80% in 3k miles when other cleaners he tried had failed . He spread the word and it's helped many Saturn owners to date .

Something you might think about if the engine has been neglected but never overheated although I don't have time to give exact instructions .

Thank you for the info. I'll try ASAP.
ed

Is the oil light flashing because of a loss of oil pressure? BAD!
Or, is it an oil level light? Rare!

Top off the oil at every fillup. Do NOT wait for idiot light to remind us who we are.

I knew several owners of Tercels. They all had oil consumption issues over 100k miles. One owner complained about valve seals, the other because the sump was too small...... As far as I could tell, maintenance wasn't a top concern for any of those owners.

You could try cleaning out your engine with some Auto-RX. web site Cleaning up rings and seals can make a big difference. It worked for me with a 20 year old Civic.