Low coolant level warning but the reservoir is full
 

I replaced yesterday the coolant reservoir and 2 hoses. I think that it is caused by air trapped in the system what do you think?

Did you try running the engine with the heater on hot? That usually shifts a bit of air.

leave the overflow container open turn the heat on and wait til the car is up to temperature. that will get all the air out for sure.

if the tank is aftermarket, the majority of the time they do not manufacture the float in the tank correctly and does not work with the level sensor correctly.

Thx for the advice i will try it this afternoon. Its not an aftermarket tank . I bought it from the junkyard and it is in very good condition

No. It didnt work!! I saw 4 bubbles of air coming out but then nothing . Im still getting the error code !! Fuc* that it is not a big problem i wAnt to enjoy my car

I have an I6 so what i did might be different. Your X should have the same engine as those E39 540s. Go on these forums and search for "bleeding the cooling system"

bimmerfest.com

bimmerforum.com

I hope they help you out.