My d16y8 has been burning oil here and there for a while now. There are days when it would burn more oil then other days. I was thinking maybe oil control rings were shot.

I took out my plugs and took a flash light and looked into each cylinder. Both cylinder one and two have normal carbon build up. But cylinders three and four both have oily wetness on top of the piston. The plugs aren't covered up in oil and still look normal.

I noticed that my oil cap on the threads pieces had broken off and could this cause something in the head to be damaged?

The car still runs good, doesn't misfire, doesn't leak, has new valve cover seals etc. I haven't compression test or leakdown tested the motor yet.

I'm just wondering if this could possibly be the head that needs a rebuild or not.

 

Answers should come from doing wet versus dry cylinder compression tests, as well as leak down tests.

 

Generally, smoking under load would be seals, smoking just with higher RPMs would be rings. But a compression and leakdown test like RonJ@HT suggested would be ideal.

 

If I drive normally like in the city. I can get away with quite some time before needing to fill up on oil. But if I drive under load like freeway driving and going over mountain passes etc. Then I'll be using more oil. My cat finally failed, by clogging up.