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What's this tube for???

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bigboystoy
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What's this tube for???

Post by bigboystoy » Mon Jan 13, 2020 4:48 am

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
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Past toys:
1979 Volvo282GT
1988 Porsche 944S
Current toy:
1986 635 CSi

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jps635
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Re: What's this tube for???

Post by jps635 » 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
'85 635csi JPS (RA2-66)

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86_6series
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Re: What's this tube for???

Post by 86_6series » Mon Jan 13, 2020 12:07 pm


bigboystoy
Posts: 63
Joined: Wed Feb 13, 2019 4:22 am
Location: Melbourne, Australia

Re: What's this tube for???

Post by bigboystoy » Tue Jan 14, 2020 4:10 am

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
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Re: What's this tube for???

Post by plip1953 » Tue Jan 14, 2020 8:56 am

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
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1988 Highline 635 CSi

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86_6series
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Re: What's this tube for???

Post by 86_6series » Wed Jan 15, 2020 1:14 am

# 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

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jps635
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Re: What's this tube for???

Post by jps635 » Wed Jan 15, 2020 5:49 am

Phil, see below
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'85 635csi JPS (RA2-66)

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86_6series
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Re: What's this tube for???

Post by 86_6series » Wed Jan 15, 2020 8:55 pm

jps635

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

Thanks
Bob V

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jps635
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Re: What's this tube for???

Post by jps635 » Thu Jan 16, 2020 5:22 am

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)

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