Weird heater problem - United Bimmer Community

**Wolf** · 11-23-2011, 06:55 PM

I hope someone can help me with this one, I get hot air out of the Driver side but the Passenger side blows cold no matter what. I checked the sensors tonight and the connections on the head unit (turn nobs)
BTW, 1995 325IC, I really need the passenger side to work soon, it is getting friggin cold....
Any help is appreciated
Wolf

**Manolito** · 11-24-2011, 01:24 PM

If your car uses the same heater control valve that the newer e36s use, it is a dual water valve, one side for each side of the dash, and one side is not opening.

As I recall, there are three wires to the valve. The middle supplies power, and the side wires are grounds provided by the heater controls. If you power the middle pin and ground the side connector on the valve, you should hear the valve snap from wide open to completely closed. If both sides sound OK, you can try opening the passenger side while the car is running and warm and make sure you get hot air to the passenger side, but I am guessing that only one side will snap open because the water valve is subject to corrosion and heat and gunky water and is more likely to fail than the dash control unit.

Replacing the water valve on a 6 cyl e36 is a PITA because of tight quarters. Easier if you remove the air plenum from the firewall, but pulling that air plenum loose from the firewall if it has not been removed in 16 years may be a two-man job. I nearly did a back flip over the radiator when mine finally broke loose when I removed it to replace heater hoses. Speaking of heater hoses, if you replace the water valve you definitely want to replace all the heater hoses at the same time. They are due. Don't forget the hose under the intake manifold. You need to remove the cap on the oil filter to get your arm under the intake manifold.

**Wolf** · 11-24-2011, 01:50 PM

Hey Manolito
Thank you for the info, Just point me to the Valves before i rip the car apart at the wrong end

. I was hoping not to exchange the Valve part as it shows in the Bentley it is major weekend work.......

**Wolf** · 11-27-2011, 04:36 PM

is there a way to check from the dash controls first? I have lately a lot of problems with my cluster and other things. What about the Hot-cold wheel above the radio? Does that unit give signals to the Valve unit too?

**Wolf** · 12-01-2011, 12:14 AM

one more question.....
Where in the hell does the "Flapper box" sits people at Pelican parts talk about?
I would like to check that before i have to take out the dual valve unit
Thanks
Wolf

**Manolito** · 12-02-2011, 08:41 AM

I looked at the parts book and your car does have a dual water valve.

There are a couple of flapper doors beneath the dash that are often suspected but rarely found guilty of heater problems. I have never touched one on a BMW, which is good because they are likely tough to get at.

The wheel at the vent in the dash is a simple mechanical valve. I have not seen one of those fail, and you say you are getting no heat at all on the right side, and that wheel impacts only the vent it is on.

Looks like your car uses the later style climate control computer. Although not related to this problem, you may want to bookmark post on my web page for future reference:
http://www.frontiernet.net/~papi/Clim_Ctrl.html

**Wolf** · 12-02-2011, 08:59 AM

Hi Manolito
I do have the old style controls (Knobs) and I finally found an articel last night on the Flapper Box and where it is located. Apparently the plastic arms what control the flaps like to break with age and I found a tutorial how tix that problem with parts of a coathanger

Whatever my findings are, I will post here
Oh BTW, on the right wheel above the Radio what switches from hot to cold when you turn it the cable was out of the guide whole so it does not actuate properly. I might have done that when i installed the new stereo, i don't know
Your help is really appreciated and many thanks
Wolf

**Wolf** · 12-05-2011, 07:25 PM

took my Glove box out today and found this little leaver sitting between glove box and heater box but can't see where it belongs to. oh great, can't upload the pic.....
How do you upload here or can you only link to another page?
Wolf

**Wolf** · 12-06-2011, 04:23 PM

ok, leever thinghy belonged to the vent flap above the glove box....
Still no heat on passenger side and my little Blower in the controls what sucks the air in never shuts off, even running with no key in ignition and draining my Battery

**Wolf** · 01-17-2012, 06:13 PM

Hi everyone
I finally got around to take the BMW apart and found out something really weird.
After dismantling the center console, unplugging the AC control unit and taking out the screws from the Heater-Box cover, not only my heat started working normally, also my RPM Gauge works again what failed about 5 month ago. I started to put everything back together and noticed that as soon i plugged back in the AC Controller my heat stopped working on the passenger side again. Just unplugging it again wouldn't do anything until i shut of the car and restarted the engine. It seems that somehow the AC Controller messes up things with the heat.
Does anybody have an explanation for that?

Wolf