today i was driving andnoticed my temp guage reading about half way up when normally it stays at 1/3. when i got home i cecked the coolant level and it was low. So i added some but when i started the car up to besure i had enough collant in it tiny airbubbles started to show is this a problem or is it air in the system

 

if the coolant was low there is air in there.

 

how long before its all out