525I mystery vacuum pipe

[whiskychaser]

HI. I have a 92 525i auto. In the hose between the inlet manifold and servo is a one-way valve. Off this valve is a small T. Clearly this should be connected to something as its dragging in air. Was told by BMW it may go to the trottle housing behind the butterfly or to the DME through the bulkhead. Cant find anywhere it could go. Anybody help with this one plse?

[Jon K]

A pic is necessary

[joshua43214]

its a vacuum source for accessories. It may not be used on your car, if you can't find a loose vacuum hose anywhere, just put a cap on it.

[t_marat]

Like this?:
http://www.bimmer.info/forum/showthread.php?t=20681&page=2&highlight=vacuum

[whiskychaser]

A pic is necessary
Attached (hopefully) is a pic of the one-way valve showing the small outlet at the bottom. Blocking it off improves the idle but thats only to be expected. I cant find a hole in the bulkhead a pipe may go through or any loose plumbing.

[Jon K]

Ah yes the elusive "random" vacuum nipple. Some people have something on it some people do not. It supposedly leads to the cabin or something... I dunno I dont have it.

[joshua43214]

Just put a cap on it if you cant find any accesories it runs to.

[t_marat]

I had it open also. Saw in other cars that it is capped. Did the same with mine.

[shogun]

I am not sure if that is the same function. On E32 750 in German specification the throttling valves (EML type with motor) have an additional disturbance air valve installed. On other spec cars these studs on the throttling valves are just closed with a rubber cap. Function of this valve is to open this valve during the inspection for TUV (German road certificate testing) to see if the ECU reacts very quick on additional air or vacuum in the lines. Emission related subject. Here is such a valve installed, my Japanese version does not have one, just a plug
http://www.bimmerboard.com/members/shogun/original/motorv12StoerventilDK.jpg

[t_marat]

I think whiskychaser does not havea an EML. or am I wrong?

[whiskychaser]

I think whiskychaser does not havea an EML. or am I wrong?
Not sure what EML stands for. But if its is a fly by wire throttle, mine doesnt have it. Thanks to everyone for the help and suggestions.

[whiskychaser]

I spotted the small outlet was used on my good friend e34.535i.sport's car. The small vacuum hose that comes off it disappears into the bulkhead near the heater inlets on his. While this hasnt caused me a problem in nearly 3 years, its bugged me now and I'd like to know where it connects, what its for and if I should have one too! :D.

[ArnZ!]

Yeh mine has been blocked off too.

[e34.535i.sport]

We need to get to the bottom of this mystery! :D

It's interesting as I don't have many interior 'luxuries'... In fact I would say almost definitley less that the Whiskychaser, as I know he has air con which I don't...

Inside I have normal heater/blower facilities, OBC, radio, heated rear screen, electric sunroof and electric mirrors.

What about you Colin?

[whiskychaser]

We need to get to the bottom of this mystery! :D

It's interesting as I don't have many interior 'luxuries'... In fact I would say almost definitley less that the Whiskychaser, as I know he has air con which I don't...

Inside I have normal heater/blower facilities, OBC, radio, heated rear screen, electric sunroof and electric mirrors.

What about you Colin?

I dont know if they are luxuries, but my front seats are electric as are their headrests. FWIW it also has rear headrests and what I think are called 'big' arm rests front and back. It has those little speakers in the front doors and a rear sun blind (that gets loads of use!:D) The air con doesnt work properly as it needs some gas - I depressed the valve lifting the head off:( It has a cassette box thats really useful - for something I've yet to discover. Oh, and cruise control.

My brother made up a 'webcam on a stick' for me when I was trying to locate a coolant leak once. Will have to ask him to dig it out for me so I can have a proper look round those heater pipes. My best guess at the moment is that the vacuum is used to empty the ashtray on yours;)

[DaveVoorhis]

I spotted the small outlet was used on my good friend e34.535i.sport's car. The small vacuum hose that comes off it disappears into the bulkhead near the heater inlets on his. While this hasnt caused me a problem in nearly 3 years, its bugged me now and I'd like to know where it connects, what its for and if I should have one too! :D.
If you've got a vacuum hose that disappears into the bulkhead, you'll find it emerges at the HVAC interior temperature sensor under the dash. It's used to draw air over the sensor, presumably to improve its accuracy.

[whiskychaser]

If you've got a vacuum hose that disappears into the bulkhead, you'll find it emerges at the HVAC interior temperature sensor under the dash. It's used to draw air over the sensor, presumably to improve its accuracy.

I dont actually have the hose-just the 'T'. But John certainly does. For information, where is the HVAC sensor located and what does it do? Sounds like you are the man to solve a mystery

[DaveVoorhis]

The sensor is mounted to the panel beneath the dash. Here's a pic from a 1990 E34:
http://shark.armchair.mb.ca/~dave/525i/27Aug05/i8270432.jpg
You can see it to the right of the chime unit. I believe it's used to determine the interior temperature in order to maintain the temp set on the HVAC panel. I assume there's one on the passenger side too, but I don't recall.

[whiskychaser]

The sensor is mounted to the panel beneath the dash. Here's a pic from a 1990 E34:
http://shark.armchair.mb.ca/~dave/525i/27Aug05/i8270432.jpg
You can see it to the right of the chime unit. I believe it's used to determine the interior temperature in order to maintain the temp set on the HVAC panel. I assume there's one on the passenger side too, but I don't recall.

That settles it for me. I dont have that tube or fitting next to the 'bong'. Bet I know somebody who will be taking that panel down this weekend though;)

[e34.535i.sport]

That settles it for me. I dont have that tube or fitting next to the 'bong'. Bet I know somebody who will be taking that panel down this weekend though;)

I got one of those!!!! :D :D Memories of the steering column nut tightening are flooding back! :D

[whiskychaser]

I got one of those!!!! :D :D Memories of the steering column nut tightening are flooding back! :D
Well I'm not too clear what it does. But maybe you have a 'luxury' that I dont?:D

[e34.535i.sport]

Well I'm not too clear what it does. But maybe you have a 'luxury' that I dont?:D

Well, I have the luxury of a subtle front end clunk at the moment and the need for an oil change?! Both will be getting sorted tomorrow oce I've got some energy back! :D