Coolant Reservoir sporadically drains

[bryceorbiter]

Hey guys, I recently started having this problem. I can't find a leak anywhere and theirs no milkshake I can see. I am pulling the plugs tonight to check for coolant as well. I always keep my reservoir full and check it about once a week. It will go from full, and stay that way for a few days, then completely empty itself over the next few days. I just filled it tonight then drove it around for about 20 minutes after warming it up for 15 and it is still full. I recently replaced the upper radiator hose, thermostat and water pump. I am completely baffled as to what it could be.

 

[fantom73088]

Check the radiator cap sometimes it can blow the coolant out the over flow util it is sucking air back into the radiator. And the reservoir is empty.

 

[andyvr2]

Yup I'd check the radiator cap, I had that same problem. I checked the cap, not holding proper pressure, bought a new one and BAM! no more coolant leaks.

 

[bryceorbiter]

Found the leak today! My upper radiator hose was pulling loose from the radiator when I was accelerating. I got lucky and found coolant on my o2 pigtail when I was leaving work. The coolant happened to be falling perfectly off of the hose so that it didn't land anywhere on my car and didn't leave puddles because it only leaked when the engine was accelerating.