Coolant shot out of expansion tank VTR

[TenMillionFireflies]

Back on here as I just bought me a VTR to play with. I pulled the bottom hose off last night to make some more room for some new antifreeze. Put some in it last night and had it running for a while with the expansion tank cap off. Kept checking the level and topping it up as the level dropped - Heater was working fine, temps were sitting just around half and then all of a sudden steam started billowing from the front. When I checked, water was shooting out the expansion tank. They'd be a small pause and then it'd shoot a bit more out.

Started it back up when it had dried a bit and the heater was just blowing cold and the temperature was starting to creep up, so I think it dumped most of its coolant. Any idea what might have caused this? Never had this issue on any other car despite doing them in the exact same way. I usually fill them up, keep topping them up until the level no longer drops, replace cap, bleed, top up if needed and bleed once more.

[Furioman]

have a look at this guide that a active user made

How to Bleed

[MartinObviously]

Originally Posted by TenMillionFireflies

Back on here as I just bought me a VTR to play with. I pulled the bottom hose off last night to make some more room for some new antifreeze. Put some in it last night and had it running for a while with the expansion tank cap off. Kept checking the level and topping it up as the level dropped - Heater was working fine, temps were sitting just around half and then all of a sudden steam started billowing from the front. When I checked, water was shooting out the expansion tank. They'd be a small pause and then it'd shoot a bit more out.

Started it back up when it had dried a bit and the heater was just blowing cold and the temperature was starting to creep up, so I think it dumped most of its coolant. Any idea what might have caused this? Never had this issue on any other car despite doing them in the exact same way. I usually fill them up, keep topping them up until the level no longer drops, replace cap, bleed, top up if needed and bleed once more.

It will spill off excess fluid, the full level is quite far down the radiator expansion tank.

Originally Posted by Furioman

have a look at this guide that a active user made

How to Bleed

That guide isn't totally correct.

You need to do it with the engine cold and switched off. Also turning the heaters to full makes no difference, the matrix is "open" all of the time. However having them on is a good indicator of air locks.

So when you're filling the coolant system, you close the bleed points in order once coolant flows smooth.

Radiator
Thermostat housing
Heater matrix valve (the tyre valve cap style one)