air vents

[a4to540]

i have a 97 540i 6..... cold air comes out of the back vents when heat is on.... the front ones blow warm air. anyone here know what the problem is?

[alexkid]

i think it may be your flux capacitor

its what makes time travel possible

[Qsilver7]

i think it may be your flux capacitor

its what makes time travel possible

This was just covered recently :) If your car was built BEFORE BMW started putting in the new stratified temp control dial (like on the front center dash)...that vent has historically allowed rear passengers an option to control bringing in "fresh" air...or "conditioned" (cooled air when AC is on).

The illustration below is the decades old diagram of a BMWs air distribution system:

http://memimage.cardomain.com/ride_images/1/2957/101/7390050105_large.jpg


If you don't want cold air coming out of the vent, then use the knurled dial on the LEFT side and close the vent. The rear passengers receive heated air from the vents in the floor UNDERNEATH the front seats when the driver selects the button on the HVAC control panel that directs air to the floor.

If your car has the newer rear center vent (I believe it starts with a 9/98 build date-up)...then move the knurled dial on the RIGHT to the red area (just like the one on the front center dash)...and you should get warmer air...move it to the blue area and you'll get cooler air.

(new style vent (9/98-up) which allows the rear passengers to "temper" the air from this vent just like the front passengers can from the dash's center vent)
http://www.bimmerboard.com/members/q/original/E39%20Rear%20Vent%20Ctr%20Console.JPG

Being able to "temper" the air (warm/cool) from the rear center vent changed with the introduction of the e38 7 series...then trickled down to other BMW models over the proceeding years (1998 for the e39)...below you can see in the illustration how the vent at the rear of the center console can blow warm air when it has the stratified temp dial (on the right side as seen in pic of e39 vent above).

http://www.bimmerboard.com/members/q/original/IHKA%20E38%20Air%20Distribution.jpg

[a4to540]

thanks alot buddy.....

[jamesdc4]

If your car has the newer rear center vent (I believe it starts with a 9/98 build date-up)...then move the knurled dial on the RIGHT to the red area (just like the one on the front center dash)...and you should get warmer air...move it to the blue area and you'll get cooler air.

(new style vent (9/98-up) which allows the rear passengers to "temper" the air from this vent just like the front passengers can from the dash's center vent)
http://www.bimmerboard.com/members/q/original/E39%20Rear%20Vent%20Ctr%20Console.JPG


Q,
Great info, thanks!

My car's production date is 11/97, and it has the temp control dial. (Please pardon dirty car.:smiliecap The kids own the back seat, mostly.)
http://i13.photobucket.com/albums/a282/jamesdc4/IMG_9195.jpg