Speaking as someone who had to take Infiniti & a third party warranty firm to small claims court to deal with the excessive oil consumption problem the issues with the early 2003 $ 2004 engine were bad oils rings. Infiniti actually had a secret warranty program for a while where they would install a new long block on engines that failed an oil consumption test. Funny thing, the dealership never did such a test on my car, despite being told about the oil consumption issue several times times (you can see it written up on the work order) until AFTER the warranty ended. Even then they were going to do the swap until they found out about the third party warranty. Ended up in finger point contest that required me to take both parties to small claims court. I ended up having to accept a used engine swap rather than a new long block just to make the car salable again