Coolant question....

[Maxo]

Hi all,
Was wondering if the little coolant tank to the side of the engine is meant to be full all the time or atleast to the max level it says on the side. Mine seems to empty quickly and after having serveral issues with my car and 3 different mechanics all say I have no leaks. So if I see it empty do I just keep topping it up or is it a overflow container I just leave alone or what?? It's a V6 VS 95 Commodore excutive.

Many thanks.
Maxo

[RazzaCaine]

mine does the same thing, im having to top it up weekly despite there being no leaks, its very frustrating...

[wortus]

There might be a coolant leak into the engine from a failed gasket. Have you checked to see if there is any coolant in your oil or is there coolant dripping from the overflow onto the ground after you stop the engine?
Also when you top it up make sure you top it up with a pre mix 50/50 of the correct coolant. I'd also be checking if there is any air in the system at the bleed valve.

[RazzaCaine]

i have no coolant in my oil, no air in the system and no apparent leaks, so im stumped...

[HRVATSKI_VOJNIK]

this happened to me, stopped after i changed the gasket+pump
as Wortus said, try re-bleeding the system (i found if you squeeze the top hose the bottom hose bodges up then you don't have any air but it might still do it even if there is air, not 100%) or maybe the gasket is on its way out

you could also try "blasting" the air out of the line. to do this you need to fill up the coolant, go for a drive and let the engine heat up. when you park, turn the radiator cap to the first stop (1/2 turn before the cap comes off) and listen if you can hear the coolant going though the lines to the tank. just be careful not to burn yourself.

you only need to have fluid above the min so it doesn't start sucking in air and lose coolant in the radiator, but the level will rise after you drive around as the fluid expends and goes into the overflow tank.

[KeepItStock]

Have you been using the heater?

I find when im using the heater the coolant in the resevour fluctuates, which i guess should happen a bit correct me if im wrong

[Maxo]

Interesting and thanks. After driving around abit today when I stopped I had a look and it had coolant in it almost at max I figure it's meant to go down at times and when I've been checking it's just been low but not completly empty so I guess it is working as normal? I don't know much about cars and I've heard a few people talk about "bleeding" but this is something I know next to nothing about. I think I'm totally paranoid of my car overheating after all the work I had done to it last time I just tend to think it should be fine but who knows hey..... And no I never use the heater even though im from Qld and it can be cold sometimes ( lol ) Thanks for the responces.

[BoNeZ-01]

It's possible that the coolant has just been drawn back in, as you said.

The radiator cap is designed as a return type cap, when the pressure reaches a high enough point, the cap opens to allow coolant out, to keep the system at the correct pressure.

But after you turn the car off and the system cools, the pressure drops, and creates a vacuum, pulling some coolant back in to the radiator, the idea being that radiator always remains full.

If you over fill the expansion bottle, it will just over flow from the tube out on to the ground as coolant from the engine is being let in as normal by the rad. cap, which may make it 'seem' like you are losing coolant, or look like it's getting too hot, when it's not really.

[VR38]

mine does the same thing, im having to top it up weekly despite there being no leaks, its very frustrating...

There has to be a leak, it is a sealed system and altho the level can go up and down in the overflow tank you should not have to add water.
if the system is holding pressure, confirmed via a pressure test, then it must be coming out the overflow via the cap and onto the ground...

[VR38]

But as above ^^ , are you filling it correctly to begin with???

[95 vs stato]

Let the engine idle for few minutes or drive 1km then stop and watch under harmonic balancer area on the ground and see if there is a water leak... the waterpump seal is gone in my VS and leaks water intermitantly . Mainly when system is pressurised but not hot and the engine is stopped

[RazzaCaine]

yeah im filling it up correctly, it appears to be have stopped occuring now though. i gave the car another good bleed of the system and tightened some of the hoses which had loosened so im assuming that it was probably a minor drip from one of the loose hoses. i know my waterpump is fine, its only 6 months and 5000kms old...

[JAAV]

Usualy around the intake gasket, dont see it all the time as it will evaperate, Do a pressure test when its hot. It will show up WARNING HOT WATER. Fit the tester on then run up engine then do test..