So my coolant reservoir is filling up with coolant on its own. It's never been filled in my 1 year of ownership. But just now it has been. The coolant isn't milky its just normal coolant. Am i overreacting?

 

so its usually is always at a normal level and now all of a sudden its high or flowing out?

 

There was none ever in it. Now its almost full.

 

The reservoir is supposed to have a particular level in it at all times. The fact that its been empty is not good. Wonder if this is thermostat related?

 

Could i empty out the reservoir into the radiator itself then fill the reservoir with some coolant i buy?

 

I would start by replacing the radiator cap. It might be getting weak and allowing coolant to go into the overflow at too low of a pressure. Your cooling system is designed to hold around 15psi or so, if the radiator cap wont hold, the pressure pushes coolant into the overflow tank.
Some level fluctuating is normal, but for the most part, the level should stay the same. Coolant is water based, so over time the coolant will evaporate so it would be normal to top off the reservoir from time to time.
Hope the info helps!

 

Agree with this! Try replace the radiator cap first.

 

replace the radiator cap.
Make sure the radiator if full to the rim.
fill the overflow to the "full" line

 

Thank you for your help i will do all of this.

 

* you want the reservoir level to be at full when the engine is fully warmed up....like 180 deg+. The reference marks on the tank are setup this way. Cold values are going to be totally different.

If you don’t have a real coolant temp gauge, stock gauge needle @ normal doesn’t necessarily indicate full warm. 10-15 min drive should do it.