What's this tube for???

Post here for mechanical and engine topics such as fuel issues, transmission problems, rough idle, exhaust, electrical issues, etc

Moderators: GRNSHRK, ron, bfons

Post Reply
bigboystoy
Posts: 68
Joined: Wed Feb 13, 2019 4:22 am
Location: Melbourne, Australia

What's this tube for???

Post by bigboystoy »

Whilst poking around the engine bay this morning I discovered a loose tube and I'm guessing its female partner. It disappears inside thru the firewall where the headlight adjustment tubes are.

I'm guessing its for vaccum but what does it control?
20200113_152911.jpg
20200113_152911.jpg (58.61 KiB) Viewed 5241 times
Past toys:
1979 Volvo282GT
1988 Porsche 944S
Current toy:
1986 635 CSi
User avatar
jps635
Platinum Member
Platinum Member
Posts: 872
Joined: Sat Feb 27, 2010 10:50 pm
Location: NZ

Re: What's this tube for???

Post by jps635 »

Runs to the interior temp sensor for heater control, under lower dash panel. Connects to one of the nipples under centre of manifold
'85 635csi JPS (RA2-66)
User avatar
86_6series
Platinum Member
Platinum Member
Posts: 1069
Joined: Mon Apr 02, 2007 10:08 pm
Location: West Nyack, NY

Re: What's this tube for???

Post by 86_6series »

86-635CSi
96-MB C220 SOLD
98-740i
71-Continental MK3
bigboystoy
Posts: 68
Joined: Wed Feb 13, 2019 4:22 am
Location: Melbourne, Australia

Re: What's this tube for???

Post by bigboystoy »

Hey thanks for responses. This might answer a few questions about heater issues.
Past toys:
1979 Volvo282GT
1988 Porsche 944S
Current toy:
1986 635 CSi
plip1953
Posts: 400
Joined: Mon Aug 13, 2018 4:15 pm
Location: Leeds

Re: What's this tube for???

Post by plip1953 »

jps635 wrote: Mon Jan 13, 2020 5:46 am Runs to the interior temp sensor for heater control, under lower dash panel. Connects to one of the nipples under centre of manifold
Fascinating! Are you able to explain the role of a vacuum pipe in relation to the temp sensor and more generally in relation to heater control?
Phil
__________________________

1988 Highline 635 CSi
User avatar
86_6series
Platinum Member
Platinum Member
Posts: 1069
Joined: Mon Apr 02, 2007 10:08 pm
Location: West Nyack, NY

Re: What's this tube for???

Post by 86_6series »

# 10 part
https://www.realoem.com/bmw/enUS/showpa ... Id=64_0467

Page 6413-0

Follow heater regulator- measures cabin air temp (lower left) GN/BK wire to air door control unit. Open and closing.
Also feeds A/C selector switch for heat & A/C. Guessing it opens and closes heater valve and on & off A/C compressor
along with controlling vent flaps.

On page 6413-1 the heat regulator also controls fresh air control unit.

Hope this helps a little.

https://www.millerperformancecars.com/f ... Manual.pdf
86-635CSi
96-MB C220 SOLD
98-740i
71-Continental MK3
User avatar
jps635
Platinum Member
Platinum Member
Posts: 872
Joined: Sat Feb 27, 2010 10:50 pm
Location: NZ

Re: What's this tube for???

Post by jps635 »

Phil, see below
Attachments
IMG_3772.JPG
IMG_3772.JPG (94.15 KiB) Viewed 5154 times
'85 635csi JPS (RA2-66)
User avatar
86_6series
Platinum Member
Platinum Member
Posts: 1069
Joined: Mon Apr 02, 2007 10:08 pm
Location: West Nyack, NY

Re: What's this tube for???

Post by 86_6series »

jps635

That's a great diagram, where did you find it and is there any more of that style available?

Thanks
Bob V
86-635CSi
96-MB C220 SOLD
98-740i
71-Continental MK3
User avatar
jps635
Platinum Member
Platinum Member
Posts: 872
Joined: Sat Feb 27, 2010 10:50 pm
Location: NZ

Re: What's this tube for???

Post by jps635 »

Bentley manual. There's a few similar type diagrams for various systems. Makes it easy to understand what's connected to what.
'85 635csi JPS (RA2-66)
Post Reply