I'm posting this because it seems to occur frequently...no air out of center vents.

Happened to my 95 E320 wagon about 4 months ago and I assumed it was going to be a major deal involving dash removal and I wasn't about to attempt that myself.

This morning I was working on something else under the hood and happened to notice a yellow plastic device (turned out to be a vacuum check valve) that had, basically, fallen apart.

I removed the pieces (there is another identical check valve right next to it), took it to Star Motor, they gave me a replacement (yep, gave it to me), I put it in, and all the vents are now working as they are supposed to.

These things are located near the firewall on drivers side and are clearly visible, so if you are having trouble with the vents, check this first. I was told at the shop that they see it frequently..plastic just breaks up.

I'm surprised that the vacuum leaks didn't have effects on other things but the car was running perfectly and everyhting else was working.

AH