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2005 E320 CDI *black on black with nearly every option*
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Discussion Starter #1
Need to pick the brain of some AC experts here:

2007 E320 CDI/Bluetec w/om642

AC doesn't function at all.
The pressure sensor is reporting correctly. I've already replaced the compressor solenoid valve, since that is the #1 source of AC issues on these cars. Recharged the system, the compressor will NOT pull in any refrigerant. the entire system equalizes to 40 PSI (can pressure) and that's it. maybe used an 1/8 of a can. my high and low side gauges are showing equal pressure and absolutely no change if the engines running or not. Essentially, the compressor is not compressing. According to STAR, the AAC computer IS turning on the compressor solenoid (70% actuation).

I have a fear that the compressor itself is completely fried, but wanna make sure before ordering a new one. Any tests or anything to look for that will confirm the compressor is bad without removing it and tearing it apart?
 

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87 300D 5 speed
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5,611 Posts
Compressor is likely toast. Did you see any metal shavings in the oil when changing the valve? If so the system will need to be flushed and condenser replaced.
 

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2005 E320 CDI *black on black with nearly every option*
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Discussion Starter #3
How common is actual failure with those denso compressors? Any idea?
And I mean mechanical failure, not those pesky little solenoids.

Also no, didn't notice any shavings.

The strange thing with the failure is that I was told it was all the sudden. Freezing cold AC one day, next day nothing.

Sent from my SM-N950U using Tapatalk
 

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99 ML430, 00 ML320, 05 E500 4matic Wagon
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That is the way the Denso failed on the ML320 at 220k miles. Icy one day nada the next.
Flushed, installed new Denso, drier and hooked up the AC machine. Been working great
going on four years.
 

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87 300D 5 speed
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5,611 Posts
How common is actual failure with those denso compressors? Any idea?
And I mean mechanical failure, not those pesky little solenoids.

Also no, didn't notice any shavings.

The strange thing with the failure is that I was told it was all the sudden. Freezing cold AC one day, next day nothing.

Sent from my SM-N950U using Tapatalk
I don't know how common but my C320 (same compressor as the E) failed intermittently, then permanently. First thing I tried was replacing the valve and that didn't fix things. When I pulled the compressor the oil inside had turned dark gray with glitter floating in it. I had no choice but to replace the condenser and flush the evaporator and lines. If your oil hadn't turned all glittery you've dodged a bullet. When you drain out the oil into an open container, point a flashlight at it. If you see the glitter, you'll know. Good luck.

PS: make sure the center hub of the pulley is turning with the belt. The clutchless pulley is designed to be a mechanical fuse. If the compressor seizes up it won't throw the belt. The center hub should always turn with the belt even when the AC is off.
 

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2005 E320 CDI *black on black with nearly every option*
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1,026 Posts
Discussion Starter #6
I did make sure that center bolt was spinning, that was the first thing i checked. So most likely the compressor isn't seized. The drier and compressor is what holds the majority of the oil right? I think my next step before i order parts is to open that drier up and see whats inside.
 

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E250 Bluetec Sprinter250 Bluetec
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Do proper troubleshooting and the best site I know for it is You are being redirected...
It shows W210, where you can read sensors on climatronic, when only few W211 have climatronics with REST button, who will allow the same.
All rest need a scanner to read AC sensors.
Pay attention to notes, who indicate that you need to do sensor calibration test before performance test.
What temperatures you've tried to recharge system at? With my weather r134 can gives 60 psi, what is about min for compressor to start pumping.
 

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87 300D 5 speed
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I did make sure that center bolt was spinning, that was the first thing i checked. So most likely the compressor isn't seized. The drier and compressor is what holds the majority of the oil right? I think my next step before i order parts is to open that drier up and see whats inside.
Most of the oil will be in the case of the compressor although you'll find it on every surface inside the AC system.
 
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