Hi
I've noticed, when visually checking the level of coolant in the expansion tank, it looks quite low. However, if I wait for the engine to cool, then take the cap off to check the level, there's a hiss and slight bubbling of coolant as I release the cap and the coolant is then sitting at the correct level, between the min. and max. mark. The next time I drive the car and check the level, again the coolant will appear quite low, unless I turn the cap and release the pressure.
Is this normal, because the coolant system runs under pressure? Or should it not be doing this? I'm concerned I might have air in the system or something because I've not bled it properly.
Cheers.
