The center vent (above the climate controls) on my 300E doesn't flow anywhere near the same volume of air that the side vents do. Is
this normal or do I have malfunction of sorts? If so, what is the probable cause and solution? I did some research in the archives, but
didn't find much detail.

...Kevin

The center vents on that vehicle are operated by vacuum to a switch . The switch or the lines going to the switch may be bad. Or there may be some blockage to the vents.

my '86 300E stopped blowing out of the center vents all together! My mechanic removed the dash and replaced the vacuum 'pods' (about ~5 of them(?)). It started working fine after that. In other words, it was related to a vacuum leak.

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Mark Herzig
1992 500E (82,000 miles)
1987 300SDL (105,000)

If it happens to one in specific, it is probably that vaccum pod. If the dash has to come off to repair it, be sure to have them all checked.

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