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Bringing this back up even though its a few months old. I just replaced the compressor in my W211 E55, and this thread was the explanation for why it did not work.
The original compressor was without a diode, and the replacement included it, and of course it doesn't run!
Now that I know that the parts catalogs aren't reliable for this distinction, have any of you found a way to correctly choose the proper Denso compressor? I found a Nissens which looks correct based on the photo, if the photo can be trusted.
Bringing this back up even though its a few months old. I just replaced the compressor in my W211 E55, and this thread was the explanation for why it did not work.
The original compressor was without a diode, and the replacement included it, and of course it doesn't run!
Now that I know that the parts catalogs aren't reliable for this distinction, have any of you found a way to correctly choose the proper Denso compressor? I found a Nissens which looks correct based on the photo, if the photo can be trusted.
Thanks for the quick reply. Do you intend to check EPC or another resource? I have EPC, I just no longer trust the vendor or store catalogs. Denso's search doesn't even list my original part, US or EU.
EPC will give MB part number, not the Denso number.
Also, post a photo of the old compressor sticker, and/or the photo of the electronic control valve installed at the back.
Alternative, if the new compressor is not in the car, photo of the sticker and the valve area. If I could see the valve completely I could try find which valve matches it w/o the diode.
There are two versions of each compressor, with and w/o the diode. So swapping the same valve type for one w/o diode is another approach
Looks like I am in the same boat. Saturday, my car had A/C, Sunday, it did not. Looked at things with iCarSoft - pressures are fine (and confirmed at the fill valve - lots of refrigerant pressure) but I have a mag clutch fault.
So the question is - at 81K miles, all in Florida so the A/C compressor has been running hard for nearly all of it - is it really worth replacing just the clutch? Or am I better off sucking it up and just getting a new compressor. I am not afraid of having to refill the system, I already did that once this year to replace the pressure sensor. From eEuro, the compressor is not THAT expensive in the grand scheme of things, ~$425 for a Denso. And lots easier to do it now than wait for it to fail and send shrapnel through the system. So call it $350ish more to replace the whole thing. Not chump change, but then again in theory I might not have to touch it again for a LONG time.
I should add, I got bit by this once before. Had a Volvo where the clutch died, replaced just the clutch, then less than a year later the compressor grenaded with all the fun that results in. I spent a TON of money on getting cold air in that car.
I'm just glad it waited for me to finish driving from Maine to Florida! That would have been super annoying with no A/C, even in early November.
Kevin Rhodes
Port Charlotte, FL
'14 E350 wagon
Last edited by kevinr1916; 11-27-2023 at 06:08 PM.
Looks like I am in the same boat. Saturday, my car had A/C, Sunday, it did not. Looked at things with iCarSoft - pressures are fine (and confirmed at the fill valve - lots of refrigerant pressure) but I have a mag clutch fault.
So the question is - at 81K miles, all in Florida so the A/C compressor has been running hard for nearly all of it - is it really worth replacing just the clutch? Or am I better off sucking it up and just getting a new compressor. I am not afraid of having to refill the system, I already did that once this year to replace the pressure sensor. From eEuro, the compressor is not THAT expensive in the grand scheme of things, ~$425 for a Denso. And lots easier to do it now than wait for it to fail and send shrapnel through the system. So call it $350ish more to replace the whole thing. Not chump change, but then again in theory I might not have to touch it again for a LONG time.
I should add, I got bit by this once before. Had a Volvo where the clutch died, replaced just the clutch, then less than a year later the compressor grenaded with all the fun that results in. I spent a TON of money on getting cold air in that car.
I'm just glad it waited for me to finish driving from Maine to Florida! That would have been super annoying with no A/C, even in early November.
Kevin Rhodes
Port Charlotte, FL
'14 E350 wagon
the magnet is an electric part. Its life does not correlate with compressor effort.
Changed mine on W212 and still running w/o any issues
All the vehicle listed on my signature are still on the original compressors. The 2014 and 2015 have not been recharged yet. The 2008, 2012 and the 2014 are Florida only cars, while the 2015 was a Connecticut-Florida car before hand
the magnet is an electric part. Its life does not correlate with compressor effort.
Changed mine on W212 and still running w/o any issues
All the vehicle listed on my signature are still on the original compressors. The 2014 and 2015 have not been recharged yet. The 2008, 2012 and the 2014 are Florida only cars, while the 2015 was a Connecticut-Florida car before hand
I didn't say it did - but the compressor IS wearing out with every revolution it spins... It could last another decade, or it could grenade itself next week. I am not a fan of being penny-wise and pound-foolish, and given I have the tools to deal with the refrigerant, it looks easier to just replace the whole thing than fiddle around with the clutch itself. I'd probably take the compressor out of the car to do that anyway - changing it in place looks like a PITA just to save a few bucks in refrigerant that I have sitting on the shelf anyway. Unless there is more to removing the compressor than it looks - it seems very accessible with lots of room to get at the bolts and get it out of the car.
Do you need to reset anything with Xentry after replacement? Or does it self-test and clear the fault on it's own? I have access to a Xentry setup, but I will have to have it shipped down from Maine.
I didn't say it did - but the compressor IS wearing out with every revolution it spins... It could last another decade, or it could grenade itself next week. I am not a fan of being penny-wise and pound-foolish, and given I have the tools to deal with the refrigerant, it looks easier to just replace the whole thing than fiddle around with the clutch itself. I'd probably take the compressor out of the car to do that anyway - changing it in place looks like a PITA just to save a few bucks in refrigerant that I have sitting on the shelf anyway. Unless there is more to removing the compressor than it looks - it seems very accessible with lots of room to get at the bolts and get it out of the car.
Do you need to reset anything with Xentry after replacement? Or does it self-test and clear the fault on it's own? I have access to a Xentry setup, but I will have to have it shipped down from Maine.
Thanks for the reply!
Kevin Rhodes
There was no need to use XEntry. It worked once it started.
On the topic of taking the compressor out of the bay, it is not only about saving money. I am extremely conservative about opening components (open surgery) on ANY system (being a car, a computer, a piece of software, a human, etc). The less I disturb a system, the less likely to introduce new problems. Opening a good working condition AC system, you must be careful that you may need to replace the dryer/condenser as well once exposed to the environment. Be careful that no oil leaves the system, do not disturb the Schrader valve, proper vacuum, etc. Was it a PITA? sure, but the repair was under a very controlled setting.
For example, I do not take the intake plenum out when changing the plugs unless I really want to look at the valves, or being forced required to access something else.
I do work on computer software, and I would be rich if I get paid for the times I was told: "it is easier this way, nothing will be damaged, and nothing will change with my approach"
NOTE: if getting a new compressor, be careful the seller send you the correct compressor combo. I mean with the correct "diode or w/o diode" for your car. Some people have got into trouble just because the provider sent the wrong, though look like correct, compressor.
There was no need to use XEntry. It worked once it started.
On the topic of taking the compressor out of the bay, it is not only about saving money. I am extremely conservative about opening components (open surgery) on ANY system (being a car, a computer, a piece of software, a human, etc). The less I disturb a system, the less likely to introduce new problems. Opening a good working condition AC system, you must be careful that you may need to replace the dryer/condenser as well once exposed to the environment. Be careful that no oil leaves the system, do not disturb the Schrader valve, proper vacuum, etc. Was it a PITA? sure, but the repair was under a very controlled setting.
For example, I do not take the intake plenum out when changing the plugs unless I really want to look at the valves, or being forced required to access something else.
I do work on computer software, and I would be rich if I get paid for the times I was told: "it is easier this way, nothing will be damaged, and nothing will change with my approach"
NOTE: if getting a new compressor, be careful the seller send you the correct compressor combo. I mean with the correct "diode or w/o diode" for your car. Some people have got into trouble just because the provider sent the wrong, though look like correct, compressor.
Thanks, good to know it should clear itself.
I have no particular fear of working on the A/C system - I have the tools, and I have done it many times across a wide variety of cars. I already emptied and refilled this car once to change the pressure sensor. No alternative for that job. The trick for something like this is not leaving it empty for any length of time. Let enough gas out to reduce the pressure, then plug the hoses. Only a very minimal amount of air is going to get in there while you get the part swapped and everything buttoned up again. Vacuum it out thoroughly, put the specified amount of gas and oil back in, and call it a day.
I also am in no particular rush. It's not my only car.
I'm actually a computer *hardware* engineer - I have not much fear of breaking things, lol. I take apart systems while they are up, running, and in production (enterprise storage and backup, with a side of virtualization and high performance computing/networking.
11-11-2023, 10:51 PM
