2012 Mercedes GLK 350 - A/C Cooling problem

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forumoto
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2012 Mercedes GLK 350 - A/C Cooling problem

Post by forumoto »

my ac blows hot on freeway, Cool in town what could it be.?.and Cool in park..?

Compressor has been changed yet still...

Thanks
Dougflas
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Re: 2012 Mercedes GLK 350 - A/C Cooling problem

Post by Dougflas »

Start looking at the metering device. If possible, tape a gauge set onto the windshield and give us the readings.
forumoto
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Re: 2012 Mercedes GLK 350 - A/C Cooling problem

Post by forumoto »

Metering device? You mean the manifold gauge or what?
Dougflas
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Re: 2012 Mercedes GLK 350 - A/C Cooling problem

Post by Dougflas »

forumoto wrote:Metering device? You mean the manifold gauge or what?
Negative. I am speaking of the TXV or orfice tube. There are the devices that allow refrigerant to flow into the evaporator.
Al9
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Location: Southern Europe

Re: 2012 Mercedes GLK 350 - A/C Cooling problem

Post by Al9 »

The expansion device is a TXV. This, and the compressor's solenoid valve, work together to regulate refrigerant flow across the A/C loop at all times.

Refrigerant pressure readings alone will provide little or no information, because this is an electronically regulated variable displacement compressor system. Real info comes from the PWM compressor output's signal, but this requires expensive tools to analize.
forumoto
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Re: 2012 Mercedes GLK 350 - A/C Cooling problem

Post by forumoto »

Expensive tool like which type? Are you thinking about scan tool? I have autel scan tool. Which can analyze the lice data pid of the A/C module and Engine Module, all that matter is the sensors to select for this info to display and record.
Al9
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Location: Southern Europe

Re: 2012 Mercedes GLK 350 - A/C Cooling problem

Post by Al9 »

Oscilloscopes and very expensive scan tools.

That's if you want to troubleshoot and not just toss random parts at it hoping for the AC to behave itself.

Ensuring that the system is leak-free and charged with the correct amount of refrigerant is always recommended as the first step whenever cooling acts up.
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