1. mcbrue  Jan 23, 7:01 pm
Last spring my evaporator sprang a few leaks. It is in the middle of
the dash. They had to take the whole front of the car apart to replace
it. (I think it was the evaporator - something like that anyway.) It
cost $1,800 US to do it, less than half of what Ole Heavy Karl the
local Stealership would have charged. But now when I have driven for
anywhere from an hour to two or three hours, the air gets warm coming
out of the AC vents and I have to turn it to the no-compressor setting
for a long while. Then eventualy I can get it to come back on. One
excellent inhabitant of this ng suggested it is coil freeze-up. Is
there any way to fix this? If not, I will have to sell it or give it
away and try to find a new car to replace it. But that is bad cause the

new S Klasse only has the humongous 550 cc gas eater available. And I
fear the return of gas lines like the 70s in Ca. So I won't buy the new

5.5 L engine which means I will have to go to the Rexus LS430 Kudzu
Kar.  Suggestions to fix the AC problem? The professional wrenchs at
Smilin Sams will fix it, of course, but the head guy didn't seem to
have any ideas when I called him when it happened. "
96 S420

What is not clear here is whether this happened immeadiately following
the evaporator repair or just surfaced now, 9 months later?  Actually,
it may not matter come to think of it.  Because the evaporator may not
have frozen up until recently because it was used in relatively warm
weather.

I'm not familiar with your particular model, but in general, here's how
many of them work.   There is a valve at the evaporator connection that
is controlled by a temp sensing capillary tube that goes into the area
of the evaporator coils.  When the evaporator is warm, the valve is
open.  When it drops close to freezing, the valve closes to stop the
refrigerant flow before the evaporator can freeze.  It's possible that
when they did the work, they either did not put the capillary tube back
into the evaporator properly so that it is not measuring the temp of
the evaporator, but the cabin air, or damaged it.   I would at least
have a chat with the shop that did the work and see what they have to
say.

Check your freon level... it is probably low again... you might have a leak
elsewhere instead of ol' evaporator. I know I know... piss ya off eh?

1) it sounds like they neglected to install the evap temp sensor all the way into its position OR it
has fallen out of the heater case. I doubt it is disconnected electrically, it may be bad though.
You have to remove the lower dash panel on the left side. The evap temp sensor is above the gas
pedal, in the left side of the heater case.

2) MBUSA announced yesterday that the new S600 V12 is going to be released in the US but no ETA.
I know, that is the wrong direction you wanted them to go :)