525I mystery vacuum pipe

[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! .

[ArnZ!]

Yeh mine has been blocked off too.

[e34.535i.sport]

We need to get to the bottom of this mystery!

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!

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!) 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! .

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