i decided to tak off this thread cause there were a few things i need to clarify, i may repost it when i get a chance to fix it

Also, drill a small hole (1/16) through the arrow on the thermostat to help with the bleeding.

massaging the hoses helps circulate and remove the air


:eyebrows

Whenever filling a cooling system on an M20 or an M30, it is critical that the bleed screw be left open until coolant runs out of it. Then it should be shut, and the coolant level in the expansion tank brought to the cold mark.

If that step is left out, you'll have huge air pockets and the system will take forever to bleed.

Realistically, it shouldn't take more than a minute to bleed the system on one of these cars. If you don't have coolant return in 30 seconds of 2-3k revving, something is wrong.

Also, drill a small hole (1/16) through the arrow on the thermostat to help with the bleeding.

+1

Would this be the same process on the 1991 525i ?