Is the coolant system a closed system? 2006 aveo HB

[FlaAveo5]

I cant seem to find the post I thought I posted a week ago,so I am reposting now. I guess I didnt post it correctly. I just want to know if the coolant system on my 2006 Aveo is a closed system? I mean,it doesnt have a removable radiator cap on the radiator. All there is ,is that plastic reservoir next to the firewall. Does the coolant run though it,including that plastic reservoir? I cant imagine that HOT coolant running through the plastic and not burning right trough it.

But does it? I want to add a small bottle of like Prestones Coolant 'Anti Rust-Coolant Additive' to the system, but I dont want to drain the entire system to add it. It doesnt need to be changed, so I thought I could add this bottle to the reservoir, and it would go through the system when it reaches a certain temp. and all the coolant runs through the entire system....right??

OR does this plastic reservoir only hold extra coolant, incase the system needs some fluid, if there is a leak or it gets low for some reason? So is it a closed system like that? OR does the coolant run through that plastic reservoir? It is easy to get that fluid out, and put a small pint/quart bottle of like Prestones Coolant additive to it. But if I have to drain the system to add it...then I'll pass on that. Does anyone know?

[AndrewButler05]

It's not a closed system. That yellow cap is the "radiator cap" for our cars. It is a safety cap and will not allow you to remove it if the system is hot. If you look closely at that reservoir there are min and max lines on it.

I'm not going to poke at additives (there's another mess of a thread for that), but why do you think your car needs the anti-rust additive? The coolant is my car is a peachy orange color and is perfectly clean.

The coolant is a closed system in that if all gaskets and seals are working correctly it does not come in contact with any other fluids, it shouldn't be dirty. If it's dark or smells, then it has most likely been "hot" and the engine has overheated in the past and needs drained and flushed.

[FlaAveo5]

i just figure to put in the Prestone 'anti rust and additives' stuff, to lubricate the inside of the radiator system, and prevent the radiator from corroding on the inside. Thought of it as 'an ounce of prevention'....nothing wrong with it now, but to prevent things from happening. So the super hot coolant is going through that plastic reservoir....it isnt just sitting ? So that plastic reservoir is not just sitting there doing nothing, till the system says it needs some more fluid for whatever reason? It actually has the hot coolant going through it?

[AndrewButler05]

Oh ok, that's entirely up to you on adding it. Just be wise about adding things to your cooling system, some things don't like to mix well.

I should also mention that I have never done any research specifically on those coolant additives before. I've never really known anyone to use them, and the need to has not arose as of this point. I always thought that coolant had anti-corrosive properties because of what it's made from, and as long as you kept your fluid changed regularly it was unnecessary to use additives.

That does not mean that they are bad, just throwing that out there.

Most heavier plastics can resist temperatures up to several hundred degrees. If my memory serves me correctly, our engines run at like ~230 degrees at full operating temperature. That doesn't mean it would never melt, but your engine would literally have to be on fire and then you would have bigger problems at that point.

If it was just an overflow tank it wouldn't have a safety cap, and it would just be a vented "always open" cap like a lot of older cars have.


Just my two cents.

[FlaAveo5]

oh. Ok. I didnt think of that, that the plastic could handle the temps. of a running engine. I just assumed that as the cars got more and more complex, the radiator cap,on top of the radiator, went the way of the way of most rear wheel drive and no air bags! And it did, it is now on the reservoir, instead of on top of the radiator.

That reservoir is under pressure, your right, I have opened it sometimes, when it is still 'warm' and gotten a loud HISS from it. Well I am going to read the coolant additive that I want to put in from Prestone, to make sure it is just to add more of the preventative chemicals in it, not to plug up holes or if things are wrong with the radiator. Just to add more lubricants, and anti corrosive chemicals to the coolant, to keep it runing in top shape. It is hot here in Fla.,it may be going into 'fall/winter,but it is still HOT all the time..