Hey guys. I need some advice here. I have an 06 525xi with a manual transmission purchased just in spring. Right after I bought it I had low coolant light. With a pressure testing I was able to diagnose and replace a few hoses and eventually the radiator.

Now this winter I have cold air blowing on the drivers side and a tiny bit warmer on the passenger side..so I was convinced it was the heater valves but after pulliing them out and testing with INPA they seems to be working.

Thermostat temp via hidden cluster menu is pretty much 90 deg C in city driving...

No stored codes related to thermostat or water pump

 

Probably the water valve. INPA is not going to tell you the whole story. Electrics can be fine on the valve, but the rubber seals shot (swollen and dropped in passage) and thus no water flow.

 

Very true what DavidF says. The diaphragm can be damaged in a water value and the electrics of the solenoid are working fine.

 

Makes sense...thanks guys..

I'm going to bypass the valve tonight with a plastic connector and see what I get. Will keep this thread posted.

 

How did it go? Last time I had cooler air - especially on feet - it turns out the Coolant (anti-freeze) was getting low, so there was not enough to always be going through the heat exchanger.

 

I bypassed the heater valve with a tee so rule it out and things are the same -- cold air from drivers side.

Did some playing with the analog inputs in inpa and the heater core temp with the blower fan on full is 18 deg C left and 38 deg C right.

I think it's the heater core.