No, the flap is not the cause of your (intermittent?) ac not working.
The compressor is deactivated when certain temperature or pressure parameters are reached, the flaps are not a part of this programming.

 

The service advisor at the previous dealership said something along the lines of “the flap is stuck in the hot air position and not flipping over to cold air”.

Sounds like BS based on what you’re saying.

 

No that is valid only when it's a heat blend flap, those are in the center section. But then what you would notice is that you have AC in one side and then the stuck side would be warm.
The only thing that flap determines is if air goes out the top vent that faces the window or the adjustable passenger facing vent.

 

Hello everyone, I know it's not related to the post but I'm a new W222 owner and new to the forum. I also have a problem with my W222 and I can't find a solution anywhere, the problem is on the left side, when I turn on the heat, exactly by the trim that covers the ambient lights, cold air blows out that freezes your knees. Maybe someone else has faced this problem and can help me too, I'm attaching a picture of the location where it blows cold air. Thank you, have a good day!

 

There is no vent there? How much air is coming out? Any work done on dashboard?
Would recomend a separate thread.

 

I talked to the service advisor briefly, yesterday. They just sent me an estimate for $8200 with no notes, explanation or anything. I called and we couldn’t finish the conversation between him trying to leave for the holiday any my cell signal. ($10k and I’m not upgrading the look or technology of the car at all? No way). Based on my request for a list, he sent this.

He did say I need a new evaporator coil(?). Something about snaking a camera through it and not seeing any dye inside or all the way through. (Don’t quote me on that.)

Discussions to resume Saturday. I hope to get a detailed description of what they did, why they are convinced this is the problem.Parts $2475.02

Labor $5459.03

= taxes and fees $8187.74

 

The dye is for leak detection, if they saw dye on the evaporator then they are planning to replace that. This would be for a leaking system.
Labor sounds very high, are they double counting the dash removal for the duct and evaporator?

 

First of all , thanks for the answer.
It's just the ventilation in the glove box but it's closed, I don't know if work has been done in the area, I'll ask the previous owner. There's quite a lot of cold air coming out, my wife said she needs to get a blanket to put on her knees. I don't know how to open a new thread, maybe an administrator can help me. Thanks!

 

Not sure why the duct and actuator are not listed in the parts (unless I’m missing something).

I’ll confirm tomorrow, but I believe he mentioned not seeing any leaks, although the freon was low, so that prompted the technician to snake a camera through the evaporator.

Why in the world there would be low freon after all this service is beyond me.

Again, if this is bad, shouldn’t it stop working permanently and not be ok each time for 2-3 weeks?

Going back to when I picked up the car from dealer A, the technician’s notes claim he got it to blow at the right temperature the entire time. Two comments on that:
1) From the moment I sat in the car once I was handed the keys, it wasn’t working. This is the one time (in 5 separate service appointments) it already wasn’t working when I drove off after picking the car up.
2) I’ve been concerned about investigating the ac in cold weather. This started in the summer. I proceeded, hoping this would be a simple fix, but also to tie all the work history together, trying to avoid coming back in 6 months in the spring for them to say it’s a new problem. If one pays attention, you can tell when the car is not cooling the air, even with these temperatures. It feels less “crisp or brisk“ than putting my hand outside the window, and has a slight smell, reminiscent of mildly stagnant or non-conditioned air.

I would go to my other mechanic and ask if they can do that work (I think I’ve seen a few Mercedes in there that were in crashes) so this may not be too extensive for them.

I still just need to be confident I’m not throwing money away. I LOVE this car. But there’s a limit.

We’ll see how it goes tomorrow.

Thanks and hope your holiday was good.

 

Yes something is wierd, they are listing to replace both air nozzles (as in the part that you move manually to direct airflow) but not the duct and actuator with the fault (which if they are taking apart the dash they should do).

 

Only information I got from these guys. This is their email, per my request:


CUSTOMERS CONCERN - GUEST STATES A/C IS NOT WORKING CORRECTLY IT DOESNT BLOW "COLD,COLD AIR" ITS VERY MILD , CUSTOMER GOT A COMPRESSOR DONE IN SEPT OF 24, AND HVAC RECHARGE WAS DONE LAST WEEK. HE STATES THAT ITS STILL NOT WORKING PROPERLY AND THE RIGHT FAR VENT DOSNT BLOW ANY AIR AT ALL PLEASE CHECK AND ADVISE - APPROVED $279.95 DIAGNOSTICS

DIAGNOSTICS - THE TECH VISUALLY CHECKED FOR LEAKES AND FOUND NO TRACES. HE CONNECTED THE AC MACHINE TO CHECK PRESSURE. HE FOUND NO REFRIGRANT IN THE SYSTEM, HE CGARGED THE AC AND INJECTED DYE. HE RAN THE AC FOR SEVERAL HOURS. THERE WERE NO LEAKS PRESENT, HE USED A EVAP CORE BORE SCOPE AND DISDNT FIND ANY DYE. MEANING THE EVAPORTAOR COILS ARE NOT DRY, THERE ARE WET SPOTS, INDICATING A LEAK. + WE HAVE FAULT CODES IN THE AAC CONTROLLER FOR THE RIGHT AND LEFT DAS VENTS.

RECOMMENDATIONS - REPLACE THE EVAPORATOR COIL AND THE RIGHT AND LEFT A PILLAR VENTS

REPAIR COST/ESTIMATE - $8187.74

BREAKDOWN -

19.5 IN LABOR $ 5459.03 - DASH AND CENTER CONSOLE NEED TO COME OUT

PARTS - $2475.02
[img]blob:https://mbworld.org/d5826149-9073-4e66-8297-73a846768931[/img]


+ TAXES AND DISPOSAL = $8187.74 (ESTIMATE)

Why the evaporator was not picked up before, even after a return visit, is beyond me. Why it seems there aren’t ducts or air flaps listed in this most recent breakdown, is also beyond me WT*? Can a reset of some sort make this work for only 2-3 weeks?

 

Yes a recharge and clearing of faults would put the system back into function and then once enough refrigerant leaks out the compressor would be turned off.

The tech is stating you had no refrigerant so the leak diagnostics makes sense, but there seems to be an error in the redacted text as that should say he found dye on the evaporator and therefore it needs replacement.
This could be your issue as long as the leak has been correctly identified in the evaporator (it happens but it's way more common for the leak to be in the condenser as it is exposed to road debris).

 

Also the parts quote is mistaken they are quoting to replace the nozzles on left and right but you need the duct and motor, like misunderstanding between tech and parts guy.

 

OP is your car equipped with rear A/C?

 

Yes

 

yes. Why?

 

I just a similar issue cleared up by my dealer. It turned out to be a sun sensor. First time I had it in, they did the refill and trace also but it did not resolve the issue.

 

What was the name of the sensor and do you know what it cost to replace? What was the similarity in your symptoms? I’m curious how it ended up being this sensor you mentioned.

 

It's listed on my work order as just a Sun Sensor. Part number 204-905-75-01. $20 dollar part. My original symptoms were that my AC wasn't blowing cold. Even after charging, my right side vents would blow 6 degrees warmer with AC on and set to low temp. Apparently the sensor was faulty so the right side didn't get the correct reading so AC didn't kick on for that side.

 

Thanks. Interesting. The more I think about it, I assume that sensor would generate error codes, which have never popped up on mine.

 

Problem identified and solved. The previous owner went to a garage to change the filters and they didn't close the lid... Idiots.

 

I thought I had pasted my response correctly a few days ago:

Finally picked up the car Wednesday after Thanksgiving and got to speak with the service advisor in person. Learned a few things:



-There is a difference between coolant and refrigerant. Refrigerant is the same a Freon (Freon is a brand).

-If refrigerant leaks, it evaporates. (This might explain no visible puddle on the ground, yet low levels observed after it sat).

-I was very clear the problem was not a charge and I wasn’t looking for them to just do that (their default response). Told them “they really need to explore the system in depth to find the problem”. They ended up charging the system as well, at no charge to diagnose (this will be the 6th time, the 5th time was a week before at the previous dealership).

-There was no evidence of refrigerant in the system after it ran for hours and then sat for a while, even though they observed no leaks. This prompted them to use the bore scope. They found evidence of refrigerant ON the evaporator coil. (I had wrongly assumed the scope ran inside it.)

-The error codes for the AAC controller are not the cause of the problem with my cooling, however it makes sense to replace them since the dash has to come out to do the evaporator. (That’s the air nozzle on the quote. He acknowledged that is weird that it’s listed as that.)

-They feel 85% sure that’s the problem. I asked about the intermittent operation and he suggests that perhaps it leaks after the system gets charged, and keeps happening. FINALLY A REASONABLE SOUNDING EXPLANATION FOR SOMEONE WHO KNOWS NOTHING ABOUT THIS. [This aligns with the feedback from @VII. I can’t thank you enough. Wish I lived in your city so I could just pay you to do it. My car would be in good hands. Hmmm, perhaps I could make this a road trip?]

-Pricing the work with my mechanic. Initial quote was about $1940 part + $1800 labor = $3740. (This quote doesn’t include the flaps or other things on the list though.) They may be able to source an original part at a better price without going to the dealership (don’t know how) but I’m waiting on that number. (This supports the double counting of labor by the dealership quote.)

-Need to decide if I really want a non-dealership to disassemble my dash, on such a temperamental machine. If not, it’s time for another car. At least the car works totally fine until the Spring. It’s too cold in Chicago now. I do feel this work should be done in warmer weather, to make sure there’s no false positive performance that isn’t caught for months.



-I do question if all of this re-charging of the system could be done at too high a pressure or too many times to cause the compressor and evaporator to start leaking? Been the same performance issues from the start of the summer. Why did none of this happen the first time? Might be neither here nor there at this point. Not sure how to prove it.



-Pissed that I had to replace the compressor. If it was really bad, and now this…. In the end, I’m starting to question the longevity of the car build. I love the car, but it’s starting to feel like I’m nearing the lifespan of the parts in general. Almost 140K miles. Too many expensive things falling apart randomly, on a car that is well taken care of. They used to last 3-400k miles back in the day. Not convinced anymore. Maybe it’s just mine? Will decide…



Learned a lot painfully. The education and support are invaluable. Thank you all.



Hope this helps the less knowledgeable people like me, on here.