Might be too thick for the oil to fit in the bearing clearance... but not as bad as if you were to use say, 50 weight.

Your engine might be worn enough that it wouldn't matter anyway.

But I don't think 10w30 is going to help your leaks much.

Goin' Round Traffic Circles @ 50Km/h!!! \m/ -- 1998 E0 SVT #2119 of 6535 \m/ -- 2003 Sentra SE-R Spec V