Heat Issues

[Xkalaber44]

Ok i am stumped, i have a 2005 325xi with the 2.5 L, the issue is the Heat does not always blow hot air, it goes to cold every once in a while here is what i have done so far
1)I have replaced the therostat
2) Replaced all the Anitfreeze
3)Repalced the upper and lower radiator hoses
4) Replaced Expansion tank Cap
5) Replaced the water Pump
6) Replaced Both Drive Belts
7)Replaced both tentioners they were bad.
all the above parts are OEM,
From all the research i have done it starting to look like the Heater Core Valve. Before i go and replace this does anyone have any suggestions?

[randy72877]

What was the process you used to bleed the cooling system?

Sent from my SAMSUNG-SM-G870A using Tapatalk

[Xkalaber44]

fill the system, run it with the heat on, fill as needed, test drive, let it cool and check and add antifreeze if needed.

What was the process you used to bleed the cooling system?

Sent from my SAMSUNG-SM-G870A using Tapatalk

[randy72877]

Try this method to bleed the cooling system. Remove the cap and bleeder screw. Fill the expansion tank with the bleeder screw removed until coolant comes out of the bleeder screw hole. Et should be full to the top at this point. Reinstall the bleeder screw now. Start the engine and rev it a little (1500 rpm) and look in the cap opening. There should be a stream of coolant coming from the side of the reservoir and you may notice some air coming out initially. After 20-30 seconds coolant stream should be solid (no more air) shut off the engine and suck out excess coolant in the et to get the correct level. Reinstall with cap and you should be good. The official bmw procedure says to turn the ignition on and heater while filling but it does nothing on a e46 except m3 because they don't have an electric auxiliary water pump like other models.

Sent from my SAMSUNG-SM-G870A using Tapatalk

[Xkalaber44]

ok i will try it tonight and let you know , thanks for the help.