What is this?

[JonnyD3487]

http://i94.photobucket.com/albums/l89/wtfmate3487/20120508_205455.jpg

That's my dead pedal on bottom left, so you understand where you're looking.

Under the dash there's that black plastic piece with a hole in the middle and i can hear it sucking at idle and deceleration but under any engine load it goes quiet. Seems like a vac line to me but it looks like its supposed to be there. Any ideas what that is?

Thanks

[tschultz]

I believe the vacuum line plugs into that and it is your interior temperature sensor. That way if you select the temp knob to a certain temperature, (with no heat coming out of the blower) the car will maintain that temperature (assuming it is working properly).

[samsonevickis]

Yup Temp Sensor!

[dm635]

And the hose connected at the intake should have a restrictor in it. If someone's replaced hoses the restrictor is usually gone. Since you siad you could hear it, it may be missing.

[JonnyD3487]

And the hose connected at the intake should have a restrictor in it. If someone's replaced hoses the restrictor is usually gone. Since you siad you could hear it, it may be missing.

If that restrictor is missing, would it make the car run bad? I'll check it tonight when I get home.

[CW6er]

Interior Temp Sensor and Tubing:
http://bigcoupe.com/phpBB2/viewtopic.php?p=68927#68927

[maxg765]

I believe the vacuum line plugs into that and it is your interior temperature sensor. That way if you select the temp knob to a certain temperature, (with no heat coming out of the blower) the car will maintain that temperature (assuming it is working properly).

Are saying our cars have some form of automatic temp control? I had recently seen that sensor when I had to remove the kick panel and all thats was attached to it for my master clutch cylinder...I figured it was a temp sensor of some sort.

So if understand your remark correctly, when not using heat or controlling any amount of on the heat side of the dial the unit can maintain a set temp in the vehicle? Does it control the amount of AC dispersed too?

I guess I should read my manual some, is it in there?

Thanks

Max

[CW6er]

Hey, these were the top of the line luxury sport coupes, of course they control the interior temp, both heat and A/C. :D :cool

The sensor in the kick panel goes to the heater regulator which cycles the heater valve open and closed to maintain a set temp. If the temp knob is either full hot or full cold, the heater valve is either always open or always closed.

The temp selected is also passed to the Evaporator temp regulator which cycles the A/C on/off when the A/C button is pushed.

[Sprocket]

Vacuum-controlled temp sensor....

Gotta love the '80's!

[CW6er]

The vacuum doesn't control the sensor, it is just used instead of a fan to draw cabin air through the sensor, Cheap and Reliable .... The BMW engineers must have been out of the office that day! :shifty :D

[Freshbread]

Not a bad idea to clean these sensors out. I've seen the "sponge" deteriorated and nearly 30 years of toe jam clogging the sensor.
Additionally I would say a good number of folks here in the valley that have had poor running conditions or have failed emissions is because that nylon hose either A) Never makes it to the nipple on the manifold or B)The Nylon hose is broken at some point coming out of the cowl/ brake bomb area.