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Greetings,

I just purchased a damaged M135i from Copart. I have replaced the whole front end, including radiator packs and crash bars. I am endeavouring to fix it on my driveway, and the process has been progressing nicely so far.


I attempted to hoover fill the coolant, but it only extracted 50% due to the presence of air bubbles in the tube. I have reached the point when I must bleed it. I have attempted the bleed technique provided (fans set to low, heat set to high with the ignition on, and maintaining the accelerator for 10-15 seconds), but I cannot hear the pump operating.
I now lack a diagnostic instrument; nevertheless, does anybody know the location of the bleed screws for bleeding the coolant and operating the engine?
I am uncertain if the water pump is functional, since I used the vehicle for around five minutes without coolant upon acquiring it, which I acknowledge was imprudent. I am now apprehensive that I have damaged the water pump.

Does anybody have recommendations on how to continue with the bleeding process?

Loosen the bleed screw located on the header tank near the cap and proceed to fill the system.

I believe the B48 uses a mechanical water pump instead of an electronic one, which would account for the ineffectiveness of the bleed operation. Examine the auxiliary belt and identify its driven components for verification.

Greetings,

Thank you for your prompt response. It appears to be equipped with an electric coolant pump. It is also stated online. The screw you referenced is a pipe that connects directly to the tank. Would loosening it when the coolant cap is already off have any implications?


I am uncertain about the next steps to successfully implement the bleed procedure. I do not see any codes on the vehicle indicating coolant issues.

The part numbers indicate it is a mechanical water pump.

similar to an image of an authentic BMW component

The authentic OEM displays a mechanical pump.

Simply fill the expansion tank and operate the engine at idle while monitoring the fluid level; air will be expelled via the little pipes back to the expansion tank.

Thank you. I believe I was examining the auxiliary pump on eBay.