Increase in oil consumption

I have a 89 toyota 4runner 6 cyl stick 334,000 miles - still runs great



for several years it has been 800 miles per qt of oil sometimes even 1000

now it is down to 600 per qt is that indication of valve caskets or rings?

how can I tell ?

there are no oil leaks visable on the ground



thanks

A compression test would say for sure, but generally if the oil consumption appears to be directly correlated with mileage (i.e. if you go on a 600 mile road trip, you’ll burn a quart) it’s probably the rings. If it seems related to time, it’s likely the valve seals. Can you see any blue smoke on startup? That would also indicate leaky valve seals, whereas constant smoking would suggest rings. At this mileage, it could be both! The V6 they used is a nice engine, but it’s definitely no 22R, which is usually the engine that goes to half a million miles in these things.

Possibly both, at 300K miles I would expect the valve seals to be leaking and the rings to be worn. It might be worth replacing the valve seals to see if that helps. Otherwise, just live with the oil consumption until you a ready to do something with the engine.

No leaks? How about start-up? Any blue smoke? How about if it sits for a day or two? I’d go with the other posters . . . valve stem seals first . . . if that doesn’t help, rings. What weight oil are you using? Rocketman

That engine is a perfect candidate for RESTORE engine treatment. This stuff fills in the fine scratches on the cylinder walls to help raise compression and reduce oil burning. I’ve used this product in high mileage engines that have had excess oil consumption. And if this stuff didn’t completely stop the oil consumption, it sure slowed it down a hell of a lot.

Tester