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Discussion Starter · #1 ·
Can anyone help me with an odd problem?
My other car is a 1994 540i. This is the one that's causing the trouble.

My aircon and heating has always worked well. Until 2 weeks ago that is.
An intermittent rattling noise started that seems to come from behind the glove box.
The air con still worked, and I thought the noise was something loose uder the bonnet.

2 weeks ago, the aircon stopped and the heater blows hot all of the time. No matter where you put the controls, you get hot air. Great for the summer hey!

If I press the a/c button now, I get an occasional smell that is similar to burning leaves!

I gather that the E34 is famous for heater problems (my previous 535 wouldn't get hot at all), but this one is just weird.

Any help would be most appreciated, especially as I'm using the 540 at the weekends now until I repair my M5 which is poorly, having decided that it didn't like having blades on the cooling fan, so it shed most of them into the radiator! AArrrgggghhhhhh!!!
 

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Sounds like your heater valve has gone south, mine is the same way, its stuck open so it blows hot air all of the time, i just pulled the fuse for the blower until i get it fixed.



holtsaber said:
Can anyone help me with an odd problem?
My other car is a 1994 540i. This is the one that's causing the trouble.

My aircon and heating has always worked well. Until 2 weeks ago that is.
An intermittent rattling noise started that seems to come from behind the glove box.
The air con still worked, and I thought the noise was something loose uder the bonnet.

2 weeks ago, the aircon stopped and the heater blows hot all of the time. No matter where you put the controls, you get hot air. Great for the summer hey!

If I press the a/c button now, I get an occasional smell that is similar to burning leaves!

I gather that the E34 is famous for heater problems (my previous 535 wouldn't get hot at all), but this one is just weird.

Any help would be most appreciated, especially as I'm using the 540 at the weekends now until I repair my M5 which is poorly, having decided that it didn't like having blades on the cooling fan, so it shed most of them into the radiator! AArrrgggghhhhhh!!!
 

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holtsaber said:
Can anyone help me with an odd problem?
My other car is a 1994 540i. This is the one that's causing the trouble.

My aircon and heating has always worked well. Until 2 weeks ago that is.
An intermittent rattling noise started that seems to come from behind the glove box.
The air con still worked, and I thought the noise was something loose uder the bonnet.

2 weeks ago, the aircon stopped and the heater blows hot all of the time. No matter where you put the controls, you get hot air. Great for the summer hey!

If I press the a/c button now, I get an occasional smell that is similar to burning leaves!

I gather that the E34 is famous for heater problems (my previous 535 wouldn't get hot at all), but this one is just weird.

Any help would be most appreciated, especially as I'm using the 540 at the weekends now until I repair my M5 which is poorly, having decided that it didn't like having blades on the cooling fan, so it shed most of them into the radiator! AArrrgggghhhhhh!!!
Mines the same if its any consolation! Been trying to find a good second hand heater valve but they dont seem to exist! Im a bit afraid to ask the price of a new one.:eek:
 

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Discussion Starter · #4 ·
Excuse my ignorance here, but is the heater valve the part under the plastic cover on the passenger side of the bulkhead?This seems to be the area the rattling noise is coming from.

From what I can make out, given that the cover seems to be secured from the underside, there is a solenoid valve [heater valve?] under here. Does anyone know where it is controlled from so I can check the voltage coming to it. It may be the electronics playing up perhaps?
 

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Yes since u are in the U.K. passenger side, its the solenoid valve, they are about 125 USD brand new, the go bad, some say u can tap on them with a hammer, but i tried it and it did not work
 

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Discussion Starter · #6 ·
e34it said:
Yes since u are in the U.K. passenger side, its the solenoid valve, they are about 125 USD brand new, the go bad, some say u can tap on them with a hammer, but i tried it and it did not work
I've just found the wiring diagram for the heating / aircon system, so I'll check out the voltage to the valve first.
I think you are right though. Any idea how much of a job the valve is to replace?
 

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It should take minutes, its right at the top so all you would have to do is pull the old one and put in the new one
 

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e34it said:
It should take minutes, its right at the top so all you would have to do is pull the old one and put in the new one
Yes changing it is simple,Ive done it about 3 times! I did own a e34 535 once that the hammer treatment worked on now and again,but it doesnt really get you anywhere.
Does anybody know what sort of voltages should be at the plug???
I have put a multimeter on mine and the voltage does vary depending on where the temp. control switch is.Hotter being the lesser voltage.(all but 12 volts on full cold setting)
 
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