I'm a guy so obviously I can't say I've experienced this, but my girlfriend has and she talks about it ALL THE TIME. We're both medical students with good knowledge of anatomy, and after lots of discussions over it and come to some pretty good conclusions.
The first things is that, yes, a vagina usually always has a "vagina smell". This is caused by several different things. Mainly, the vulva (the "vaginal area", whatever you want to call it) contains merocrine sweat glands. These are a different type of sweat glands that are on most of your body, but they are in your armpits as well. The sweat they release tends to be "thicker" and contains chemical compounds and pheromones that smell. Since that's a "cramped" area and you probably sweat a lot down there, the sweat probably causes a lot of the smell. Also, the vaginal lubricants can also contain chemicals and pheromones that smell: we (my gf and I) have found that this really changes a lot, usually depending on what week of her "monthly cycle" she is on.
This is probably pretty obvious too, but pee smells. When you pee, some of it gets spread around down there and stays, so that would definitely add to the smell. That's the easiest to fix though: just go wash and the smell will be gone. Washing will help with the sweat smell too, but you can't really control the lubricant smell, if that is part of it. Overall though, a vagina is going to smell like "something": you can't completely get rid of it unless you wash like every thirty minutes. It's not bad though, it's just a normal thing. So as long as it doesn't "stink", it's ok if it smells.
Anyway, I hope that helps you somewhat