[bmwhitman]

During the coolant bleeding process, do you close the cap/cover or leave open on the coolant tank? If it's closed , is it completely closed tight with the arrows lined up?

[Sgop335]

I leave the cap open and keep filling w coolant as the level goes down. I dont mess w the plastic bleed screw since the last one broke and caused issue.

[Efthreeoh]

Fully closed

[Efthreeoh]

Originally Posted by Sgop335

I leave the cap open and keep filling w coolant as the level goes down. I dont mess w the plastic bleed screw since the last one broke and caused issue.

This is incorrect.

[juld0zer]

My preference is to get the pump running (floor the gas method for electric pumps or run the engine for mechanically driven pumps) with the expansion tank cap off for 5mins with a jug of coolant ready to pour in because the level will rapidly drop once the pump starts working even if you brim the tank before starting.

Once the system stops drinking, i put the cap on.

The bleed screw isn't really necessary on these tanks because the system self bleeds but i do undo it and let out any air briefly.

It is good practice to order bleed screws, stopcock and any common fragile hoses when doing a cooling system repair.

[Efthreeoh]

Originally Posted by juld0zer

My preference is to get the pump running (floor the gas method for electric pumps or run the engine for mechanically driven pumps) with the expansion tank cap off for 5mins with a jug of coolant ready to pour in because the level will rapidly drop once the pump starts working even if you brim the tank before starting.

Once the system stops drinking, i put the cap on.

The bleed screw isn't really necessary on these tanks because the system self bleeds but i do undo it and let out any air briefly.

It is good practice to order bleed screws, stopcock and any common fragile hoses when doing a cooling system repair.

Maybe it's preferred by you, but for the N52/54-55 with the electric pump it is not the correct procedure. The beed screw lets air escape the reservoir while the coolant fills it and from the system as air is pushed out of the head back into the reservoir, which is where the bleed screw is situated on the reservoir.

The correct procedure as published by BMW is fill the reservoir until coolant runs out the bleed screw, then fully close the screw and reservoir cap, then run the water pump.

[dsuraci]

I did a coolant flush on my 2013 328i E92 Coupe this weekend, and everything was going smooth until the bleeding process (expansion tank cap on and bleeder valve closed). I put the key in the ignition, hit start button until dashboard lit up, heat setting on 84, fan on low, held gas pedal down for 10 seconds and the bleeding process started (heard the water pump engage). After about 10 seconds, the process stopped and dashboard went off. I tried several different combinations, but same result (kept turning off). I was extremely frustrated, but then stumbled on the fix (keep it from shutting off). Put the headlights on low beams, then the process runs full 12 minutes and completes. I just wanted to share this, just in case some one else was seeing the same situation.

Cheers,
Dean

[Jklad]

I was watching my Bmw tech doing this in my car just last weekend. After changing my coolant expansion tank and new radiator, he initiated the bleed procedure, ran it twice, and left the coolant tank cap off the entire time.