What can cause a empty overflow tank. My radiator is always full with coolant.
I added some water in there for the time being. Keeping a eye on it every other day I drive it. Could've been a bad bleed from my recent timing belt work...If it was full and now it's empty then there is a leak somewhere. As coolant expands when hot it flows from the radiator into the overflow. Then when it cools it gets sucked back into the radiator from the overflow. It's a closed system so in theory the levels shouldn't change over time.
Yes indeed. The factory overflow have 1 tube leading outside and 1 connected to the radiator spout.Is it? I thought the top of the overflow cap had a hose that vented down to the atmosphere, so perhaps evaporation could eventually cause the tank to be empty.
Good point! Closed system was a bit strong of a term...not like the older BMW systems where the overflow tank is actually pressurized.Is it? I thought the top of the overflow cap had a hose that vented down to the atmosphere, so perhaps evaporation could eventually cause the tank to be empty.
It's all good, I was genuinely asking curiously because I wasn't sure if mine was broken or something LOL. Mine has a hose that just goes down there, but when I got the car, it had originally been sliced shorter by the belt I think or something, so I wasn't sure if it was supposed to be connected to something or not. I never had any troubles, but if it is supposed to be a closed system, I'd want to fix it. Or maybe the overflow tank cap has some sort of valve to keep the system closed unless a release is needed. But I didn't think it would be all that complicated.Good point! Closed system was a bit strong of a term...not like the older BMW systems where the overflow tank is actually pressurized.
It was green from previous owner. It doesn't seem like a mixture of any kind so I believe its a complete flush. And yes it has been messed with because previous owner installed a spectra radiator. Not sure if the thermostat been changed.Definitely keep an eye on it over time! It could be a very very slow leak, or just evaporation. It might have never been messed with before in the almost 20 years.
Though, I hope you dind't just add green coolant to the system like that without a complete flush unless it already had green...