turbosix

Never heard anyone mention burning oil but i was cruising to work like 6 months ago at a steady 85mph and looked down to see my low oil level light had come on.

I immediately slowed to around 60 and the drop of ~1100rpms seemed to make the light go off. No biggie, I added a quart once I got to work, checked the level and forgot about it.

Fast forward to yesterday... exact same scenario. Get to work and check the level and it is right below the "low" marker while i was parked slightly on an incline so it wasnt 100% accurate.

added another quart and all is well again.

wtf, burning a quart over a few months.... car has never done this before and it does *not* leak... i have not read this to be an issue with the 1UZ... have i just missed threads on this?

LS400_Fan

Do a compression test and see what kind of conditions the rings are in.

turbosix

car doesnt smoke, makes good power. has about 130k on it.

if i get bored i might bother but i figured someone on here might have known something i didnt

LS400_Fan

A good possibility then could be valve seals. When valve seals go bad, they can't keep a strong enough seal against a high vaccumm condition in the engine (ie on deceleration). So oil gets literally "sucked past" the seals and you will see some smoke on deceleration.

sometimes it is only noticable at high speeds and/or high rpm deceleration. Especially at that mileage, it would be a good guess. I even saw a tutorial online on how to do it yourself. It really isn't any different than any other car i've worked on.

Pressurize the combustion chamber
Compress the spring
Take out the keepers
pull put the valve seal
put in new seal
put spring back on
put keepers back in

Move to next valve.

That's a "rough" how to but that's how you do it.

turbosix

if thats the case i'll prob do it when i do the timing belt & wp

pito

Just to add

With bad valve seals if you were to let the car sit at idle for a few minutes and pull off you would see some blue smoke out the exhaust pipe. If your rings themselves were bad you would have a constant blue smoke cloud coming out when you give it some gas.

I suggest checking the oil when it is cold to get an accurate reading and be careful about adding oil when the car is hot. You could be overfilling the crankcase innocently thinking you are saving your engine.