[W126 Coupe] AC Problem Part 3
Tom Oelsner
toelsner at mindspring.com
Tue Oct 11 16:48:57 EDT 2005
Guys,
I think you are all circling around the issue and not hitting the mark. The
system worked fine for a month and changed only a week ago. The scenario is
that at speeds below 75 mph the air is not blowing cold, only cool. At
speeds at and above 75, the air is blowing cold.
Markus,
I'll check the high and low side temps tomorrow.
Tom
-----Original Message-----
From: mbcoupes-bounces at mbcoupes.com
[mailto:mbcoupes-bounces at mbcoupes.com]On Behalf Of Markus Meyer
Sent: Tuesday, October 11, 2005 1:27 PM
To: mbcoupes at mbcoupes.com
Subject: RE: [W126 Coupe] AC Problem Part 3
Tom,
Have you ever had a bad compressor replaced, or is the only work
done to your system the items you just listed? Reason I ask is, I had issues
a few years back, and after 3 different attempts, it was finally traced down
to a bad suction line off the compressor that had a piece of metal stuck in
it. That caused the restriction, which got worse with each new compressor
and recharge. First one last a year, second one a month, third one two days.
I gave up, took it to Satish who figured it out and had the system
corrected. If you look at the papers coming with the BENZ compressors (don't
know about other brands) it says right on there - replace suction line too
and receiver/dryer. I know for a fact my local guys didn't do that, so
either they can't read, didn't read, or the local compressors don't come
with that info.
In your case its hard to know. After they checked that your system
had a vacuum, you say you recharged it. How? Did you measure the high and
low pressures to make sure they were correct? Does the high side get so hot
you can't touch it, and the low side so cold it shows condensation on it? If
not, there is a problem right there (like mine). Just looking in the sight
glass may not be enough. When they evacuated, did they flush the system too?
When mine was done in the end, Satish said it looked like coke coming out at
first, they kept running it through until it finally looked more like
sprite.
Markus
--- On Tue 10/11, Tom Oelsner < toelsner at mindspring.com > wrote:
From: Tom Oelsner [mailto: toelsner at mindspring.com]
To: mbcoupes at mbcoupes.com
Date: Tue, 11 Oct 2005 13:12:38 -0700
Subject: RE: [W126 Coupe] AC Problem Part 3
I charged it. Again, the system has been working fine for a month.
This is
something new.
-----Original Message-----
From: mbcoupes-bounces at mbcoupes.com
[mailto:mbcoupes-bounces at mbcoupes.com]On Behalf Of
airedale at sbcglobal.net
Sent: Tuesday, October 11, 2005 1:10 PM
To: Mercedes Coupes Mailing Lists
Subject: Re: [W126 Coupe] AC Problem Part 3
Did they charge it too? Why not take it back to them with your
complaint?
John
----- Original Message -----
From: "Tom Oelsner"
To: "Mercedes Coupes Mailing Lists"
Sent: Tuesday, October 11, 2005 2:56 PM
Subject: RE: [W126 Coupe] AC Problem Part 3
> The system was evacuated by a shop and then had the gauge left
in place
> for
> several hours to check for leaks. All clear on that front. The
system is
> fully charged. How does one go about looking for restrictions in
the
> lines?
> Tom
>
> -----Original Message-----
> From: mbcoupes-bounces at mbcoupes.com
> [mailto:mbcoupes-bounces at mbcoupes.com]On Behalf Of
> airedale at sbcglobal.net
> Sent: Tuesday, October 11, 2005 12:51 PM
> To: Mercedes Coupes Mailing Lists
> Subject: Re: [W126 Coupe] AC Problem Part 3
>
>
> Did you do part 1 yourself? If so did you evacuate the system to
get the
> moisture out? If a shop did it take it back to them. To part 3.
Is there a
> restriction to your condenser or evaporator coil, I have seen
items pulled
> through the return air that restrict air flow. Under charging
will cause
> the
> evaporator to freeze up and impair cooling. The usual air that
comes
> through
> my supply vent in my '91 560SEC on a 90 or so degree day is
between 50 and
> 60 degrees. I notice the AC systems in the 89 through 91 hold
more R12
> than
> the 86 through 88. I do not know about the models before that.
> John
> ----- Original Message -----
> From: "Tom Oelsner"
> To:
> Sent: Tuesday, October 11, 2005 1:32 PM
> Subject: [W126 Coupe] AC Problem Part 3
>
>
>> ok...here we go again. Just as a reminder;
>> Part 1. Get the AC running. Replaced the compressor O rings,
replaced
>> the
>> receiver-drier, new AC belt, no leaks at all and rock solid.
Charged the
>> system. cold air!
>> Part 2. Belt squeal. Belt keeps loosening (stretching?).
retightened
>> twice
>> and loose again even though the idler pulley is tight. Any
ideas?
>> Jonathan, it is a Continental belt.
>> Part 3. THE NEW ONE. Had very cold air until about a week ago.
Now it
>> is
>> only really cold if I am going above 75mph or if the outside
temp is
>> around
>> 70F. At lower speeds the air is somewhat cool at best. Engine
temp is
>> definitely in range with AC on, 85C to 95C(?) and there is
still plenty
>> of
>> refrigerant in the system. Any ideas? Thanks for your thoughts.
>>
>> Tom Oelsner
>>
>>
>> The MB Coupes Website!
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>
> The MB Coupes Website!
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>
>
> The MB Coupes Website!
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> Postings remain property of MB Coupes, L.L.C.
The MB Coupes Website!
W126 SEC Mailing List
Postings remain property of MB Coupes, L.L.C.
The MB Coupes Website!
W126 SEC Mailing List
Postings remain property of MB Coupes, L.L.C.
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