I have a 90 4runner and this beast is eating about 2.5 qts. of oil between changes. The plugs look normal and there isn't anything hitting the ground. there doesn't appear to be any serious leakage around the valve covers so where could all the oil be going? what should i be looking for? i thought the plugs would be my indicator for bad rings but maybe i am misinformed. any help is appreciated.

 

How long do you go between changes, what weight oil do you use, do you see any visable smoke? I think that if all the cylinders are burning it equally, then i dont think that it would nessasary show up on your plugs, unlike if one was just burning it, then that plug would be pretty nasty, how many miles do you have on it? If it does smoke, does it do it on startup or all the time?

 

I am pretty adamant about following the propoganda that says every 3k miles and I have tried going to 10w-40 hoping it would slow the oil loss a little. There is a bit of white exhaust at the tailpipe, mostly at startup, but that is it as far as smoke. The engine has 161k on it.

 

Check the backside of the valvecovers for leaks using a mirror to see down there.
Then check the bottom of the engine for leaks as well.

If all is bone dry, the do a compression test and a leakdown test.
If all looks good there then the valve seals may be going on the head.

 

From the smoking, it could be the head gasket.
Check the radiator and see if there is any oil in there.