climate control issue

[Takimo]

so i told my trusted mechanic these 2 problems, #1) i always wait temp gauge to reach middle before opening heater, but as soon as i open heater, the temp gauge drop to 1/4 to the cold side, and it slowly get up to the middle.



#2) no matter i put the heater 20 degrees , 26 or the maximum 32... it always feels like it blow extreme hot , like 60degrees ...



he told me it was the thermostat and coolant sensor, he change the part but the problem still here... anyone can help ? could it be the climate control unit ?? please help

[80stech]

There is a small fan in the climate control that draws air in for the sensor through a tiny grilled section on the face of the climate control, maybe check if that is clean.

[Takimo]

hmm ok will check that , how sure are you about that fix ?

[wpoll]

This post about an e38 IHKA might help you check/clean it fan.

Repairing buzzing noise from HVAC



(image from mario778 on Bimmerboard)

[80stech]

It might not even be that complicated. Maybe just the little screen on the front face is covered with lint.

[Gregory891]

Sounds more like the heater control valve (under hood, near the left front strut housing on my 2002 E53).

[Qsilver7]

Originally Posted by Takimo

so i told my trusted mechanic these 2 problems, #1) i always wait temp gauge to reach middle before opening heater, but as soon as i open heater, the temp gauge drop to 1/4 to the cold side, and it slowly get up to the middle.

#2) no matter i put the heater 20 degrees , 26 or the maximum 32... it always feels like it blow extreme hot , like 60degrees ...

he told me it was the thermostat and coolant sensor, he change the part but the problem still here... anyone can help ? could it be the climate control unit ?? please help

Not sure why you do #1...set the IHKA control panel to AUTO or if you have the IHKR control panel...just turn it on and let the system do what it is designed to do. There's a "cold arrest" feature that won't blow cold air on the passengers (when the system is working correctly).


In regards to problem #2...I would say look into the water valve (aka heater valve which is what 90% of the forums call it...but officially it is called the water valve by BMW). It is Y4 in the pic below. Here are also some links (to the TIS website) that explains temperature control and the functions of the heating & air conditioning functions that might help bring some light to the issues you're having:

• https://www.newtis.info/tisv2/a/en/e...-valve/Xfp8OOC
• https://www.newtis.info/tisv2/a/en/e...-right/XedxJAX

[Takimo]

well it let the engine reach optimal temp faster ..



do i need to replace coolant if i change water valve ?

[crystalworks]

Originally Posted by Takimo

well it let the engine reach optimal temp faster ..

do i need to replace coolant if i change water valve ?

Yes. You will lose some during the replacement process that will require a top up and bleed.