Coolant issue - possibly pressure issue? Help!

[crazyjay91]

Hi all,

I've been searching around the internet but haven't found any answers.

Basically, my coolant level keeps dropping when/after running the engine (comes up on dash as low). But as soon as i open the cap and the tank de-pressurises the tank fills up again to the maximum mark. It's not actually losing anywhere the coolant as such, it's just not releasing the pressure. If I leave the engine to go cold it still doesn't come back up to max until I open the filler cap on the header tank!

Does anybody know what is going on? I've checked the cap but can't see a pressure release hole or anything on it!

Thanks in advance!

 

[crazyjay91]

Anyone?

 

[kyleseo]

Could be an airlock somewhere. Mine did something similar after replacing the hose to the header tank and not bleeding any air out. Turned car on and coolant was low, opened header tank and level returned to normal. Been fine since.

Could be a small hole somewhere that lets out a negligable amount of coolant but on the cool down could suck air back in.

 

[crazyjay91]

Could be an airlock somewhere. Mine did something similar after replacing the hose to the header tank and not bleeding any air out. Turned car on and coolant was low, opened header tank and level returned to normal. Been fine since.

Could be a small hole somewhere that lets out a negligable amount of coolant but on the cool down could suck air back in.

Thanks Kyleseo - time to investigate!