I was filling my 99 Civic Si on a slope and didn't gauge it well. When I measured it on even ground I saw this. It's considerably over-filled. Should I drain some out? I plan to anyway, but I'm interested in getting a more informed take.

 

Yes, drain it out. Just add 4 quarts next time - don't worry about trying to get the level on the dipstick correct.

 

Leaving it over filled like that can allow the crank to froth the oil (create lots of air bubbles) which in turn can cause the engine to starve of oil as it sucks air instead of oil at times.

Yes, recommended to drain some out.

 

Good to know. I drained the excess out today, so it's all good now.

 

Can potentially blow seals too, I've seen 2 of the cars I work on have seals blow because owner didn't bother to address an oil leak and kept overfilling oil to keep from going low.

 

You could remove the oil filter, empty what you can, reinstall it, let the car run for a few seconds, kill it, recheck the oil level, and repeat as necessary in order to get the level right. If that seems overly complicated, it is.

 

I handled it by just loosening the oil drain bolt and removing it for a couple of seconds while still holding it, then quickly putting it back on. It was easy to get into place while the oil was pouring out, and as soon as it was in place the oil stopped pouring out.just wiped things off and tightened it as normal after that.

The oil level was very slightly under the top line afterwards, so I added in a tiny amount, and now it's perfect.