Hey everyone,

My 328i has good heat for about 30 minutes and then starts blowing out cooler air. Took it to the mechanic and he insisted new waterpump and thermostat/housing would do it. Picked it up and still blowing cool air after about 40 minutes of driving. I'm not sure if i'll take my car back to him as this might get expensive. Any thoughts?

The cool/hot dial is all the way over to red and the heat is displayed at 85 degrees.

Those are very prone to problems with your dash control unit. Search the web for answers and you will come across this issue. The solution for me was to replace the head unit and it took care of things nicely.

Your heating coils may have gone bad...I wouldn't go back to that machanic neither!! Clearly he didn't fixed the problem you addressed.

Some BMWs have a seperate heating circulating pump that needs to be replaced when this happens. The pump and thermostat didn't need to be changed because the car wasn't running hot or overheating. I wouldn't go to that mechanic because it doesn't sound like (from what info you gave me) he knows what he is doing. It could be the heating core but the pump would be my guess since I am not under the hood.

heater core may have gone bad

The heater core ....Its found under the passenger side dash I think.....