328i coolant level sensor replace . . . bleed the system ?

[enf1945]

Hi all

You must take the coolant out of the expansion tank
when you replace this sensor.

But ive seen writeups where they say you have to bleed the cooling
system after doing this.

Why?

You havent drained out the coolantfrom the whole system.
Isnt it just like having a low coolant level ?
how does air get back in there?

thanks

[jclausen]

There is still air being introduced to the system, fill it run it if the needle stays in the middle your all good if not bleed it

[gc325is]

The expansion tank has 3 main openings. One cap, one level sensor and one engine return. The engine return path may let air into the system.


(There is the bleed hole and overflow tube too)





https://images-na.ssl-images-amazon.com/images/I/41e93l-zySL._SS40_.jpg








https://images-na.ssl-images-amazon.com/images/I/81aymdWCxZL._SX466_.jpg

[Eric93se]

If you could free both hoses and then possibly FLIP the tank (all hoses still attached) then it MA be possible to swap out the sensor. Be sure to use a new o-ring.

[enf1945]

One way to do replace the sensor is lift up the fan shroud.
The bottom radiator hose is in the way so you just can pull the sensor down.

I know you have to remove the shroud cover. Thats easy.
Is it just those two pins on each side holding in the shroud ?

Will this work?

Thanks

One writeup says there are brackets that hold the shroud to the Radiator
so i guess there are no pins underneath.