I don't think that's too soon at all. As a matter of fact it would let you know how the engine is doing with break-in, and it would also show if you have an internal problem.
A sample at 4k miles should still show moderately high silicon and copper, but other then that all should be fairly low. I think Nissan did such a good job with these engines we could probably dump in Criso Oil and get good results... :lol:
A sample at 4k miles should still show moderately high silicon and copper, but other then that all should be fairly low. I think Nissan did such a good job with these engines we could probably dump in Criso Oil and get good results... :lol: