Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help

Go Back   PeachParts Mercedes ShopForum > Technical Information and Support > Tech Help

LinkBack Thread Tools Display Modes
Old 10-04-2001, 11:26 PM
pmizell's Avatar
Benz Zealot
Join Date: Jun 2001
Location: Houston, Texas
Posts: 838
Recirculated air?

First off, as I'm unaware of later MB chassis designs so I can't speak for them, I'd just like to say that the 124 design with default setting of outside air was bad engineering.

Not only that, but to have the system not "remember" your preference for recirculated air when you start up the car and having to hit the dash button every time you're behind a smoking car is a pain in the #%#$ too.

To top it off, the "recirculated" setting doesn't seem to truly keep out outside air, at least not in my 300E. It could be a problem with my particular car, but I can still smell traces of unwanted outside air with the little red button lit up.

Anyone else have this same problem, or feel as I do?

Reply With Quote
Old 10-05-2001, 12:06 AM
JCE's Avatar
JCE JCE is offline
Down to the Wear Bars
Join Date: May 1999
Location: So Kalifornia
Posts: 2,189
Actually, the recirculated air was probably an effort to make sure no mold built up inside the AC system. My 88 Acura Legend had foul odors, and they kept insisting I was using the recirculation button as a default, and handed me a factory bulletin that said recirculate should not be used for more than 10 minutes as it allowed mold to grow, and that I should always shut off the AC and use only fresh outside air thru the system each time I was within 5 minutes from my destination!!! Their point was to never use the recirculate button except to cool down the hot car during the first 5 minutes of driving, then use AC/outside, and for the last 5 minutes, use non-AC outside. I kept explaining that was what I did, except for the last 5 minute procedure, but they wouldn't do anything about it!

There is also an unanticipated benefit to a default outside air position. About 10 years ago Atmospheric Chemists did an experiment on what setting was best in traffic jams: recirculated or outside air settings. On every car they tested, recirculated air tended to 'capture and concentrate' outside air pollution (seepage around windows and door frames, poorly closing vent doors, etc.) and always recirculation allowed worse levels inside the car than either 'fresh air' setttings, or than the outside air at window level!

My 98 C230 defaults to outside, and I believe is time limited to the duration on recirc, just like my 87. Hope this helps.

2003 Firemist Red/grey leather SL 500
2015 Palladium Silver/black mbtex GLK 350
1987 Smoke Silver/burgundy mbtex 300E Sportline (SOLD)

Click to see 87 300E
Reply With Quote
Old 10-05-2001, 01:48 AM
Registered User
Join Date: Jun 1999
Location: Surrey, Beautiful British Columbia, Canada
Posts: 750
well said John. all honda cars i owned and still use do exactly
that, and so with my 89 300e.
Reply With Quote
Old 10-05-2001, 08:23 AM
N. Gilbert
Posts: n/a
I too have noticed this while sitting in the Detroit traffic jams. If I select re-circulate, I expect it to stay in that position. After 10 min. it changes back to outside air. I thought it was yet another electrical quirk... It is distracting since by the time it changes back, my mind has focused on something else. I am reminded it has changed when I get a cloud of fumes in the car. Maybe I should be patient and the car will eventually have me trained...
Reply With Quote
Old 10-05-2001, 08:05 PM
Registered User
Join Date: Jun 2001
Location: Omaha, NE
Posts: 962
The reason MB engineers set up the climate control system to default to outside air was simple: SAFETY. Remember, this is the company that engineers its hoods to be springy so that unwary pedestrians will bounce off; the company that heats up windshield washer fluid so it doesn't freeze when it hits your windshield; puts sensors on its brake pads to warn us when brake pad material is getting thin . . .

For those of us in cold winter country, recirculating cabin air in the winter is a good way to almost instantly fog up one's windows. I've done it with a Honda I once owned, and almost every day in the winter see drivers with completely fogged-up windows.

My owner's manual tells me that the boys and girls in Stuttgart set it up so that you get recirculated air for 30 minutes after hitting the switch if ambient temp is above 45 degrees F, and only 5 minutes if temp < 45.

I think it's a really ELEGANT solution to human forgetfulness.
'93 400E
Reply With Quote


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
Rebuilt Turbo & New Air Intake - Pics! TomJ Diesel Discussion 34 09-14-2005 07:39 PM
Heat/AC work. But not much air from vents when heat is on Khameleon Diesel Discussion 12 01-15-2003 07:51 PM
Help... blowing hot air through vents JimVelca Tech Help 4 11-04-2002 03:55 PM
Seeking Advise re: Air Filter Issue pauldmtr Tech Help 1 05-12-2001 03:53 PM
Air filter housing for 1991 420SEL BENZ-LGB Tech Help 1 05-11-2001 05:18 PM

All times are GMT -4. The time now is 03:06 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page