[hellorockview]

Having trouble figuring out why I don’t have heat in my 2010 328i (E90).

Vents are all set to heat. Cranked it up to 84° at full blast. Nothing.

The only time the car produces heat is when it’s been idling for a while.

The car doesn’t have a temperature gauge, so I’ve already gone through the menu to check the temperature before and after driving. That’s been normal, but we decided to change the thermostat anyway. Didn’t make a difference.

We don’t think it’s a blocked heater core because the car will produce heat after idling. I am hearing some sort of percolating type of noise, but not sure what that could be. (The noise seems to only be at idle and I only started hearing it after a deer struck that side of the car.) I also just had the radiator replaced and the proper bleed procedure was followed. And was repeated.

The initial problem was that the driver’s side vents were blowing cool air, while the passenger side was hot. Now it’s blowing ice cold air the entire time I’m driving.

Any ideas on what to check?

[lowrydr310]

Could still be a blocked heater core, or an air bubble in the system especially since you hear a percolating sound.

First check that all the mixer flaps are functioning properly. INPA will give you all the temperatures and positions.

If that checks out, try a coolant bleed, very easy to do.

If you still have no heat I'd flush the heater core, both ways. I created an old post years ago where I rigged up some connectors from the hardware store to use my garden hose and flush the core.

[vxracer]

Just something to add, the heater bypass valve valve also be a culprit. I believe that is the problem I have, but I am in a slighty warm climate, so I have not gone through the troubleshooting process yet. Heater core, valve, flaps, air in the system, etc. The usual issues, so I have read.

[gbalthrop]

Originally Posted by vxracer

Just something to add, the heater bypass valve valve also be a culprit...

AFAIK, MOST E9x vehicles in MD & NC do NOT have "Heater Valve" or a valve to shut off coolant to Heater Core.
If your vehicle DOES have such a valve, it would be located at base of Left Strut Tower per attached ISTA ScreenPrint.

To diagnose OP's issue correctly, he needs to use INPA/ ISTA or such to monitor Cooling System activity with engine running.
For instance, use Activation or Triggering screens to monitor:
1) Thermostat Heater Activation, along with Coolant Temp;
2) Coolant Pump % of Max speed, along with Coolant Temp;
3) Radiator Fan % of Max speed, along with Coolant Temp;

ALL those screens can be used to observe function under DME control, WITHOUT over-riding DME Control.
BTW OP, you don't say what engine you have. N51 or N52? Temp sensors differ between those engines.
First suspect is Temp Sensor signal as received by DME, E-Fan (Radiator) running, etc.

If you understand HOW the Engine Cooling System works, that Live Data will offer clues of what to test NEXT.
DIAGNOSIS without Part$-Throwing is suggested.
George

[phils2]

I'm just waiting for someone to come along and say
"Have you got the scroll in the middle set to red?"