I have a slow leak in my engine coolant but it's not bad enough to fix (would cost a lot) so I just refill it every like, 6 months or so. Today I did it but I kinda went like an inch or two above the top most fill line. Is this bad, or can I get away with it? I know it's bad to overfill oil but that's because it will put too much stress on the moving parts, the coolent is just kinda sitting there and gets circulated, so I'm thinking it's not a big issue.