I have a 1989 300E . Can anyone advise
what can be causing the following. I
turn the temperature to a maximum temperature setting and keep it running for a while, when I turn the heat off the hot air is still emerging for well over 10- 20 minutes instead of cold air

Michael

It take awhile for the heater core to cool down. Unlike domestic cars these do not have blend flaps that isolate the cores, the monovalve does that.


Joe

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Also the air comes out of all three outlets-it seems that
the switches that regulate the air flow direction :lower lower upper/glass do not respond. Also is there a fuse that regulates
the front passenger window -what can caus this to be
non-operational?
Michael

Sounds to me like you have vacuum element problems. There are several threads dealing with this. If you can't find it in a search, we can start over.

I would appreciate if you could advise
on the air distribution problems in the 300E
Michael

Air flow in your car is controled by five vacuum "elements" or little push/pull devices. They are controlled by settings on the pushbutton panel. They open and close alternately to distribute air evenly around the interior and specifically target areas like defrost and recirculation. They're a ***** to get to as evidenced by the photo below. But the system won't work without them. The one that went out on mine first was the outside air cutoff. A/C was working it's butt of but could'nt compete with air coming in at 100 degrees. All the elements may not be bad right now, but not replacing them would be foolish.

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Do the buttons act as intermediate electronic switches or do they directly/mechanicaly open the air valve(s)? Did your car have one of the electric switches malfunctioning / no contact ? So I am guessing that I would have to get new switches as you suggest.
Michael

The function you choose with the buttons programs the vacuum switching devise, I had no bad switches, just elements that could not function due to ruptured diaphrams. In a proper system you should hear odd noises from inside the dash occasionally. That's the sound of the elements opening and closing various doors. At least it is on my car. It works fine since the replacement.

Cap'n that makes my back hurt just looking at that picture .
I ain't looking forward to the day I have to pull the dash on my E320.

__________________
Jim

I very much appreciate the input on the heater -actually it works
with a delay so I will leave it for some time the way it is.

The reason I asked is because I have had some smell
getting out of the vent besides the non-stop heat
and the inability to quickly change the temp.
It smelled like break fluid or Armorall, so either the person
who had the car sprayed some armorall into the plastic
compartment where the vents intake air from the
windshield or there could be some brake/ ABS fluid
leaking in the vicinity-do the 300E have a visible washer underneath the brake pump close to the round drum base or is the washer hidden?. Here it is not visible-maybe its not present. It apears as the brake pump has been replaced along with the dark round "drum" and some of the fluid seaped there and dryed onto the black drums surface.
Michael

If you have brake fluid in your A/C then you need to sell that thing!!! Jim, if you keep the E320 until it needs this service, don't fret, it's really not that bad a job. Just have something else to drive for a few days!! You've done worse tasks!!

There is no easy way of determining this .....
Appreciate the above help thanks
Michael

Michael.. there is no shame in seeking professional help. I have done this on several occasions! and will again I live by this code "I may not have the answer, but I can find someone that does". Let's find you a good tech in your area that can help you.

Any ideas?
The fumes from brake fluid could be drawn (if leaking)into the air inlet.... but into the AC through the air inlet?
Michael

Finding a MB tech sounds like a good idea
Thanks for all input.

Michael