E46 318I LOOSING COOLANT

[ideal-zn]

hi we did a pressure test this weekend and it held its pressure.

 

[ChefDJ]

Replace the pipes, replace the reservoir/expansion tank :fencelook:

Dead certain that there's antifreeze in the water? If not, no marks to be seen :fencelook:

 

[ideal-zn]

hi pipes and expansion tank was replaced last month :bangdesk:

 

[ChefDJ]

hi pipes and expansion tank was replaced last month :bangdesk:

:sorry:

Take it to a BMW specialist :thumbs:

PM Gizmo on the forum :thumbs:

 

[ChrisBrand]

Reason I ask when and how often you check is that if you recently drained the system and did not properly fill up, turn on the heater, go for a drive and fill up again then you will eventually have to top up as the coolant is making its way to all the vacant spaces.

Have you checked other things? Like say the radiator??

 

[ideal-zn]

hi i did bleed it with heater on and topped up the next day, however had to top up every day

we did a radiator pressure test and all should OK cos no reduction in pressure.

 

[Pho3niX90]

If all your pressures are fine then there is possibly a airlock somewhere? Is your thermostat in working order? Did you do diagnostics?

 

[ideal-zn]

the cap does release air when i open it so possible the airlock:fencelook: will have the thermostat checked this weekend :blab:

 

[Pho3niX90]

Have you done bleeding of the cooling system? You might want to give that a shot, could be the issue. Had same issue strangely on the 318, until I did the cooling system bleeding and after that it uses water normally.

Not sure why it worked as it doesn't make entirely sense? but I am not complaining.

 

[ideal-zn]

i have bleed the system a few times, what i noticed is when the heater is on the water pushes out the cap and not the bleeding hole, however wen its off it stays down it pushes out the bleeding hole, so not sure which is correct way

 

[Pho3niX90]

i have bleed the system a few times, what i noticed is when the heater is on the water pushes out the cap and not the bleeding hole, however wen its off it stays down it pushes out the bleeding hole, so not sure which is correct way

Give this method a shot, not sure if that is normal, however if there is no water coming from the bleed screw there might be something wrong (from my experience, which is limited)

Method: http://www.e46fanatics.com/forum/showthread.php?t=689618

It doesn't cost you anything to try that first