Cheers!

When cold the coolant level in the reservoir in my car is somewhere in the middle. As I check the manual it states that the coolant level should be at the top of the breather neck ie. reservoir full.

Is that supposed to be when coolant is cold or hot?

I guess I'm thinking about where is the room for coolant expansion as typically expansion tank are half full or 2/3 full when hot.

 

The manual states the coolant level should be at the base of the filler
neck when cold.
I have always found that it's natural position seems to be around 6mm (1/4") lower and always stays there.
Any lower and you may get readings in your speedo saying low coolant
If the level keeps dropping after top ups, it's time for investigation.

 

Hi,

Can confirm that. Once topped up the level stabilizes 5-6mm below the filler neck. Since this has been reported multiple times it seems to be the normal behavior.
It's supposed when the coolant is cold.
The excess coolant overflows to an atmospheric bottle, which is located in the LH fender. The cap of the expansion tank functions as a valve which allows excess coolant to flow into the bottle when the pressure in the coolant system exceeds 1 bar. When the cooling system is cooling down the coolant will be sucked back from the bottle to the expansion tank.

Cheers, Alexander

 

Had missed the additional tank so now it makes sense. Thanks for the help.