What plugs into the airbox, removable?

[patrickjam3s]

hey guys what is this that bolts up to the back of the air box, appears to be a sensor of some sort...
what is it?
what does it do?
if I do an airbox delete do I have to reroute it or can I just ziptie it up somewhere?

top image is what I really want to know about, Bottom Im curious if that is the MAF off the side of the intake there

http://sphotos.ak.fbcdn.net/hphotos-ak-ash2/hs124.ash2/39523_673224835115_24416728_37232150_2004467_n.jpg


http://sphotos.ak.fbcdn.net/hphotos-ak-snc4/hs941.snc4/73439_673224870045_24416728_37232152_1055390_n.jpg

[pomps325i]

Coolant return line I believe. I took mine out, zip tied it and haven't had any problems. From what I've read, it helps the engine warm up quicker or something.

[jfmjr442]

IAT - Intake Air Temperature switch

HTH

John

[drummerboi]

yup like pomps325i said, its a coolant line... you are fine if you take it out.... but might be a problem if you guys have smog inspection or something like that... might want to hide it...lol...other than that, you are fine...

[bimmerfeel]

IAT - Intake Air Temperature switch

HTH

John
Just to help keep things clear, the part OP is illustrating is a thermostat(RealOEM.com), or a "water thermostat for throttle housing" as Pelican parts refers to it as.

The IAT or Intake Air Temperature sensor, or Air Temperature Sensor, (BMW refers to it both ways), is mounted in the Intake Manifold itself instead of the Air Box.

The Air Box "thermostat" introduces warm air into the upstream intake-air shortly after startup to aid in overall throttle response in cold weather. (read COLD) Most folks seem to get by without it just fine. Like me.:) I also capped off the hot water feed to the throttle body itself. No issues there either.

[patrickjam3s]

Well I live in the north east where it gets redicuously cold, is this going to effect me

[wbarfels]

It's a secondary Thermostat for your throttle body Mine broke When my friend said "give it here, it easy to get off" while replacing a hose that went to it.so I bypassed it, and my car kept Constantly Overheating If I let it Idle like to go threw a Drive thru or car wash, And my car had a Brand new water pump on it too!

I got another from ebay for $35. and now my car dosnt overheat. As far as why it's mounted in the air box, I have no idea.
If you handle this thing remember it's Been exposed to hot coolant, and low temperature it's whole life so it Breaks easy from all the Hot/colf

Was A real Pain the a$$ problem for me