Got my coolant flushed at Valvoline back in March (if I remember right) because it was low and I wanted to make sure it was fresh. However, every time I fill it up to the "Cold Fill" section, within about a day or two it's right back down where it was before. Any ideas? I have zero leaks, no coolant smell, temp Gauge stays half way (does move up and down quite a bit, like I've never seen on another car) and all hoses look perfectly fine. Wondering if they just didn't fill it up all of the way? Even though I filled it up myself with almost an entire jug of ZEREX Coolant, and it's still not enough? Very bizarre to me.. Thanks.