2000 Dodge Stratus running warmer than normal

I have 2000 Dodge Stratus se auto trans Chrysler
2.0 4 cyl. I bought it for $300 out off someone's
yard, so minus a few things, it's been well worth
the $300, has been very reliable.
But this is the one problem I have had and cannot
figure out what is causing it. It doesn't overheat,
like get too hot, but it does get warm, like hotter
than it's supposed to. We have bought new
thermostat, drained radiator, put all new coolant in,
and just recently, like a few days ago, it even got a
little bit warmer than it has been being. If you have
any ideas please help lol. PS I think my dad would
have seen it by now and there is only minor dings
in the front of the hood from it but the girl I bought
it from had hit a deer so what if something is loose
or cracked and we just haven't seen it, and I have
had the car for about 6 months now