During the summer - a pretty hot one here in the North East, my '97 E320's
freon level dropped very low- matter of fact, only had cool air coming out
of the passenger side, hot from the driver side...
A quick trip to the dealer - - they emptied and recharged the system- but
were unable to find any leaks- but added dye along with the freon- either
the leak is extremely small or coming from the evaporator, which wasn't
checked because of it's location...
Any insight into this would greatly - greatly - be appreciated- per the
dealer, we're talking a huge job... and expensive...
A freon leak will cause all the freon to be lost so there will be NO
cooling - anywhere.
I believe your car's heater control valve or the air ducts on the left
side is defective. A/C simply blows cold when its engaged, heated air is
added back to make us comfortable because the heat can be controlled
whereas the cold is either ON or OFF, no choice.
Older M-B models have a "mono valve" to control the heater, the default
mode of these old monovalves is - full heat. It may so on your car as
well - so think heater control valve.
In my case, the passenger side air was cooler than driver side- by a
noticable difference- but we're talking cool- not cold... I was told the car
can be checked next visit to find the leak... yes, same story- rip apart
the dash to get to the evaporator... geez, what a de$ign!
Your model will have a duo valve, and I agree in this case that this
sounds like the culprit. If one side is hotter than the other it
sounds like one of the valves in the duo valve has stuck open.
As for the refrigerant loss, do you use the a/c regularly, even in
winter months? If it goes unused for a while the seals can dry out and
refrigerant can slowly escape. I've never seen an evaporator go on a
210, I don't think it's likely to be your problem.
Normal protocol is to check again either 200 miles or 1 week after the dye
has been added. If the evaporator core is leaking, the end of the drain hose
will be covered with dye (which shows up vividly under UV light). The car is
usually put on a lift to make that check. I would hesitate in having the
evaporator core replaced UNLESS the dealer has ascertained it is in fact the
If you have cold air coming from one side though (not cool, but cold), that
may not be the problem, and hope it's not. When my SL500 evaporator core
developed a leak, it required removal of the dashboard to get at it which,
as you might well have guessed, is load$ of fun! If the A/C system was open
(ie: defective evaporator core), the repairperson will probably suggest
replacing the receiver/dryer (in which the desiccant's effectiveness will
have been reduced) and inspect the heater box and all hoses while they're
--- http://www.astro-nut.com /
any AC guy that knows what there doing will put a sniffer on the unit
when its charged.
it will start screaming at the leak sight.
in your case they would stick it down the dash vent first, then go
around the fittings.
21 hours labor + parts and they are guessing?
its your $
the case, minus a few cans!
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