Who's had a failed AC compressor?
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2008 E350, 2012 ML350, 2014 E350, 2015 ML350
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Joined: Feb 2009
Posts: 692
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From: Houston, TX
2003 E55 AMG; 2013 GL550 4Matic; 2003 CL600
On the new one its more typical to what I've seen before, the red wire is a signal, and the black wire is grounded to the body of the compressor.
The old ECV had the code 2Z06W etched into it, but I can't find any reference to that.
The new condenser is in, it came with a new dryer as well, which I didn't notice when I placed the order, so I'll have a spare.
The old compessor is out. Still not sure which ECV to use with it.
Getting ready to flush the rest of the system, change valves, then hopefully close the circuit and vacuum it. I'm changing valves becuase I think the high valve was leaking, I had pressure at that cap when I last charged it.
Thread Starter
Super Member
Joined: Feb 2009
Posts: 692
Likes: 73
From: Houston, TX
2003 E55 AMG; 2013 GL550 4Matic; 2003 CL600
Ultimately replaced: the condenser+dryer, compressor, expansion valve, both schrader valves, and most gaskets (some sizes didn't match my kit of assorted gaskets).
I've previously purchased many Nissens products for MBs, mostly radiators, and they have been great. Their condenser for this car wasn't very good: the plastic frame was crookedly riveted into the metal, the transmission cooler clips were too large to fit under the OEM dust caps, and the stems were so frail that they began to break when being installed. I ended up reusing old stems.
I got a compressor on eBay which matched the EPC part number. Despite uncertainty with the ECV, it worked out fine. I confirmed that the signal and ground matched up properly before connecting it all. Its criminal how tight the space is in this engine bay, given that its a big SUV. This seems to be a normal and widely-applicable compressor, I don't know why its quoted at ~$1k at most retailers, I spent closer to $250 on it.
Did a flush with my air compressor and a bottle kit rented from Autozone, using dry air by passing it through a desiccant filter. A lot of gunk went out.
On Youtube I came by someone's tip of drilling out the old expansion valve and installing it for the flush, which allows everything to pass through better. I don't know how well the flush worked with the extra rear AC system, but it seemed to come out clear at the end.
Filled to spec with my giant Robinair machine, blowing nice and cold now!
I've previously purchased many Nissens products for MBs, mostly radiators, and they have been great. Their condenser for this car wasn't very good: the plastic frame was crookedly riveted into the metal, the transmission cooler clips were too large to fit under the OEM dust caps, and the stems were so frail that they began to break when being installed. I ended up reusing old stems.
I got a compressor on eBay which matched the EPC part number. Despite uncertainty with the ECV, it worked out fine. I confirmed that the signal and ground matched up properly before connecting it all. Its criminal how tight the space is in this engine bay, given that its a big SUV. This seems to be a normal and widely-applicable compressor, I don't know why its quoted at ~$1k at most retailers, I spent closer to $250 on it.
Did a flush with my air compressor and a bottle kit rented from Autozone, using dry air by passing it through a desiccant filter. A lot of gunk went out.
On Youtube I came by someone's tip of drilling out the old expansion valve and installing it for the flush, which allows everything to pass through better. I don't know how well the flush worked with the extra rear AC system, but it seemed to come out clear at the end.
Filled to spec with my giant Robinair machine, blowing nice and cold now!
Now enjoy it 
Thread Starter
Super Member
Joined: Feb 2009
Posts: 692
Likes: 73
From: Houston, TX
2003 E55 AMG; 2013 GL550 4Matic; 2003 CL600
AC in the GL550 went back to cycling. I opened the system and again saw debris on the expansion valve. It doesn't reach proper high-side pressures, or sufficiently cold evaporator temperatures
So I'm replacing these parts again. I was told that the new AC Compressor shipped with the right amount of oil for this system, but perhaps I shouldn't have trusted that? Seems like it ran in a low-oil state and deteriorated.
On the next compressor I'll drain it to measure how much oil there is, and add however much is needed on top of that.
The compressor part numbers vary by model year, was the ECV changed after 2013?
So I'm replacing these parts again. I was told that the new AC Compressor shipped with the right amount of oil for this system, but perhaps I shouldn't have trusted that? Seems like it ran in a low-oil state and deteriorated.
On the next compressor I'll drain it to measure how much oil there is, and add however much is needed on top of that.
The compressor part numbers vary by model year, was the ECV changed after 2013?
Thread Starter
Super Member
Joined: Feb 2009
Posts: 692
Likes: 73
From: Houston, TX
2003 E55 AMG; 2013 GL550 4Matic; 2003 CL600
I was ignorant regarding the functionality of the rear AC, but it has its own expansion valve with an integrated electric shutoff valve - A1648300184 for my 2013.
Any flushing of the system without replacing it with a full-flow adapter is pointless!
Any flushing of the system without replacing it with a full-flow adapter is pointless!
