335d mystery hose

m6pwr · 06-20-2011, 08:25 PM

There is a rubber hose (about 2 to 3 inches diameter) coming out of the backside of the air filter housing on my 335d. It snakes down toward the back of the engine but it doesn't connect to anything - - just hangs out there in the atmosphere of the engine compartment. I thought maybe mine had come loose from some connection, but there's nothing back there to connect to. Went to the dealer and checked some other 335d's and it seems to be a standard arrangement.

Does any one know what this hose is for - - its purpose and how it functions?

jopa489 · 06-20-2011, 09:22 PM

Not sure, but maybe RealOEM would help? Take a look there to see if you can find some information.

BTTGMan · 06-20-2011, 09:31 PM

That's the inlet for the optional supercharger. Good for another 70 hp!

Quasimodem · 06-20-2011, 10:04 PM

Quote:

Originally Posted by m6pwr

There is a rubber hose (about 2 to 3 inches diameter) coming out of the backside of the air filter housing on my 335d. It snakes down toward the back of the engine but it doesn't connect to anything - - just hangs out there in the atmosphere of the engine compartment. I thought maybe mine had come loose from some connection, but there's nothing back there to connect to. Went to the dealer and checked some other 335d's and it seems to be a standard arrangement.

Does any one know what this hose is for - - its purpose and how it functions?

Well, maybe they cancelled the amphibious package after the car went into production.

chromisdesigns · 06-20-2011, 10:59 PM

some kind of vent, I suspect

montr · 06-20-2011, 11:21 PM

I look at this sometime ago. I look to me that this hose is used to suck air around the exhaust manifold, instead of in front of the car, when the engine is cold. There is a thermostatic valve in the air filter box at the end of this hose.

sukutash · 06-21-2011, 05:46 AM

I also think is has to do with intake air temp. It takes hot air radiated from the turbocharger area and uses it for cold starts or cold weather starts. The valve thats on the intake box side closes once the engines at operating temp.

Thud · 06-21-2011, 06:12 AM

What happens when you blow into it?

JuppiOne · 06-21-2011, 08:36 AM

mod tube.
dealer will know what mod you have when they plug their mod computer in

Coolieman1220 · 06-21-2011, 10:10 AM

i've noticed it as well as it takes up a good chunk of the air filter in the airbox and i too have notied the springed valve. Seems to make sense that it's for hot air.

anyone w/ a d ever notice on a cold winter morning on a cold start at low rpm low speed when you're on the throttle lightly you hear a whistling noise? maybe thats it?

F32Fleet · 06-21-2011, 11:56 AM

Quote:

Originally Posted by Coolieman1220

i've noticed it as well as it takes up a good chunk of the air filter in the airbox and i too have notied the springed valve. Seems to make sense that it's for hot air.

anyone w/ a d ever notice on a cold winter morning on a cold start at low rpm low speed when you're on the throttle lightly you hear a whistling noise? maybe thats it?

More of a whirring than whistle. I think.

06-20-2011, 08:25 PM	#1
m6pwr First Lieutenant 38 Rep 374 Posts Drives: '14 335i M sport Join Date: Oct 2008 Location: San Diego, CA iTrader: (0)	335d mystery hose - the hose to nowhere There is a rubber hose (about 2 to 3 inches diameter) coming out of the backside of the air filter housing on my 335d. It snakes down toward the back of the engine but it doesn't connect to anything - - just hangs out there in the atmosphere of the engine compartment. I thought maybe mine had come loose from some connection, but there's nothing back there to connect to. Went to the dealer and checked some other 335d's and it seems to be a standard arrangement. Does any one know what this hose is for - - its purpose and how it functions? __________________ '14 328d, '13 M3 ZCP, '12 535i, '11 335d, '09 Z4 DINAN Stage II, '05 330i ZHP, '05 M3 ZCP, '02 M3, '91 328i, '90 535i, '88 528e, '88 M5, '87 M6, '95 Z3, 95 M3, '93 M5, '87 325e, '89 535i, '86 635i, '73 Bavaria.
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06-20-2011, 09:22 PM	#2
jopa489 Major General 122 Rep 6,594 Posts Drives: Anything with Wheels Join Date: Mar 2009 Location: USA iTrader: (9)	Not sure, but maybe RealOEM would help? Take a look there to see if you can find some information. __________________ X7 LCI // Incoming C7 ZR1 ZTK // Sebring + TRX // Hydro + Raptor Gen1 Roush // Tuxedo
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06-20-2011, 09:31 PM	#3
BTTGMan Banned 16 Rep 539 Posts Drives: 335xi coupe - space gray Join Date: Mar 2011 Location: Pennsylvania iTrader: (0)	That's the inlet for the optional supercharger. Good for another 70 hp!
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06-20-2011, 10:59 PM	#5
chromisdesigns Lieutenant Colonel 45 Rep 1,754 Posts Drives: 2008 BMW 335i sedan Join Date: Jan 2010 Location: San Francisco iTrader: (0)	some kind of vent, I suspect
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06-20-2011, 11:21 PM	#6
montr Captain 157 Rep 716 Posts Drives: 2010 335d, 2018 430i G-Coupe Join Date: Sep 2009 Location: Atlanta, GA iTrader: (0)	I look at this sometime ago. I look to me that this hose is used to suck air around the exhaust manifold, instead of in front of the car, when the engine is cold. There is a thermostatic valve in the air filter box at the end of this hose.
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06-21-2011, 05:46 AM	#7
sukutash First Lieutenant 66 Rep 365 Posts Drives: 2011 335d, 2020 M2C Join Date: Jan 2011 Location: Ft Worth iTrader: (7) Garage List 2020 BMW M2 KOMP [0.00] 2014 BMW 535i [0.00] 2012 MERC E63 AMG W ... [0.00] 2011 BMW 335d [0.00]	Hose I also think is has to do with intake air temp. It takes hot air radiated from the turbocharger area and uses it for cold starts or cold weather starts. The valve thats on the intake box side closes once the engines at operating temp.
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06-21-2011, 06:12 AM	#8
Thud Throbbing Member 43 Rep 1,433 Posts Drives: Join Date: Jan 2008 iTrader: (0)	What happens when you blow into it? __________________ 2014 Tesla Model S 85kwh Previous cars: 2011 335d / Deep Sea Blue / Saddle brown / sport / premium 2008 BMW 135i / 6MT 2002 Z06 Corvette
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06-21-2011, 08:36 AM	#9
JuppiOne Captain 25 Rep 691 Posts Drives: everyone crazy Join Date: Feb 2010 Location: MO iTrader: (4)	mod tube. dealer will know what mod you have when they plug their mod computer in
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06-21-2011, 10:10 AM	#10
Coolieman1220 Banned 73 Rep 1,770 Posts Drives: 2010 335d Join Date: Jul 2010 Location: New York City iTrader: (0)	i've noticed it as well as it takes up a good chunk of the air filter in the airbox and i too have notied the springed valve. Seems to make sense that it's for hot air. anyone w/ a d ever notice on a cold winter morning on a cold start at low rpm low speed when you're on the throttle lightly you hear a whistling noise? maybe thats it?
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