Hey, Mercedes Benz S class Buyers!
I wanted to share my personal experience with you about S Class that uses new refrigerant R744 (CO2) as cooling agent for its climate control system. I am based in Cyprus where temperatures are quite high in May-September months and proper cooling is essential. Since I have purchased the car I started to experience the problem with the climate control ( while the car was on factory warranty ). The climate control system was not working properly producing hot air instead of cold and passenger seat side and driver seat side had various temperatures from warm to very warm air. When you put climate control on Auto mode the fans were blowing with the maximum speed trying to lower the temperature but it was not working. I have brought the car to Mercedes Benz service station in my city and found out that there is only one service station in the whole country that can service R744 climate control systems. So the car had to be sent to another city for service after waiting for a few weeks as the service center was very busy. The service was eventually done while I was advised that there is nothing wrong and small pipe had potential Freon leakage and that was the problem. However after two weeks I have experienced the same problem. To cut the story short, it took me numerous visits to the service center, and many discussions with the service staff to find out that the problem was in the faulty air con. compressor that needed to be changed. The most astonishing was that there were no spare compressors for this model available and I have to wait many weeks until the manufacturer will have one available and will send it to Cyprus. This was horrible experience driving such expensive car without the air conditioning, wasting so many hours dealing with the problem, staying without the car and finally on top of everything I was advised that I need to pay solid amount for the replacement of the compressor, even it was clear fault of the manufacturer. What a mess and shame for the brand like Mercedes Benz!

I felt it is important to inform Mercedes community and strongly recommend to never buy a Mercedes car which uses R744 cooling agent. You will ruin your life with it. The technology is experimental, the markets are not ready for it and there is no proper service infrastructure or trained personnel that can handle climate control systems that use refrigerant R 744. I guess I was very unlucky to be one of the first to try this technology. I have read many posts on various websites from people who experience similar problems, so I am not alone. It appears that this is a very common problem.

I would appreciate to be contacted by Mercedes S class owners who had experienced similar issues with their climate control and learn how they resolved them.

 

Sounds like more of a country issue so I will continue to enjoy my MB's while they continue to treat me so well. Hopefully you get everything resolved...

 

I've had a similar experience except for the issue with the parts delivery. My car has been to the dealer three times for the AC. Now it is winter, it might still be broken, I dont know. If I had known that the car uses R744 and that the whole AC is a completely different system that works with much higher pressure and is brand spanking new in cars, I would have gotten the pre facelift... cant believe Mercedes would put such an unreliable AC in a S-Class.

 

Hello, first of all i want to thank you very much for posting this. I’m having the same exact issue for 3-4 months now and it’s really getting on my nerves. I live in The Netherlands and it gets very warm here (humidity) I got in contact with mercedes and most dealers don’t have the system to refill my ac. I got it refilled but within 2 months the same flaws you wrote down started happening again. I now know that it’s a compressor issue because of your message, if i knew this car came with such experimental things i would’ve never bought it.. unbelievable.

 

My compressor has been replaced twice now. I do get the warranty extension every year but I had to get the customer assistance center to cover my deductible cause the car has run more than 130.000 km now. Someone who has the same issue told me to get it refilled every year during inspection, supposedly the reason the compressor dies is that the pressure in the system gets too low and that somehow makes the compressor break? No idea why. Either way, I’ve been trying to sell it for 8 months now unsuccessfully. Considering to get a lawyer involved for Mercedes to take it back with a premium. They offered a ridiculous amount of 30k for trade in, when the cheapest cars anywhere online go for 45 and up. Mine has the warranty, new breaks etc. decent condition.

Really unhappy about this still. I can only warn anyone of buying the car with facelift and euro spec.

 

i’m guessing mine got too low then…? I currently have 167,000 kilometers and i’m pretty sure this is the first time the ac got refilled on the car (lasted a month) the warranty expired half a year ago. I don’t know if they will help me out with this free of charge, i’ve been calling and going to dealer to dealer for 3 months. If it can’t get fixed i hope i manage to sell it, i never wanted to do that tho the car is in perfect condition and drives like a dream. I also have no clue how to get a lawyer involved at my age. I’m only 22 years old :/

 

With that mileage I’d be very surprised if it hasn’t been exchanged. How long have you had the car and what year is it?

 

i have the car for a year now exactly, it’s a late 2019 and i put 50,000 kilometers on it myself

 

Sorry to hear about your nightmare with the R744 system. You’re not alone many S-Class owners report similar issues. The tech is too new, service is scarce, and repairs take forever. Mercedes needs to fix this fast. Avoid R744 until they sort it out. Hope you get a proper resolution soon.

 

Curious, are you saying Mercedes put this refrigerant into new production W222s for certain countries outside the U.S.?

I just did a search in the W223 forum for 'R744' and got no results so perhaps this compound has never been used in U.S. cars?

 

What is the benefit of R744 anyways

 

The W223 does not have R744. They phased it out already cause it is inherently trash. Only some W213 and W222 facelift with the 560 engine have it in Euro spec. Sounds like a cruel joke? It is. Btw, the source of this is that they had to stop using the old refrigerants that have worked fine for decades for environmental concerns. Mercedes tried to do it extra ecological and safe by using R744 which is just CO2. But the system has to run on very high pressure and it turns out they can't get it under control. So they use the same crap everyone else uses now which is dangerous when you have an accident. Because of the high pressure the whole R744 AC system is completely different to the regular one. Just parts are over 10k $, so exchanging it to say the US spec is not a financially feasible option.

 

Ah, see, mine is an earlier facelift. They did make some changes to the compressor I think, later models seem to have less issues. Then it is possible you are in for your first exchange. If it is under warranty and always serviced by MB you should try and have the records checked though, that could help you to get a goodwill repair if say it was broken before.

 

Today i tried calling Mercedes again, and to my surprise yet again they said the person that knows about this system is not reachable, and they will call me back which they never do.

 

Over here smaller branches will often times not even have the system to test and or refill your AC. You might want to go to a big Mercedes dealer. Ideally Mercedes directly if you have that in NL, like, not a franchiser.

 

Wait till you find out who owns / owned the patents for R-12, R134 and R134yf. Then, once you understand how patents work and the incredible timing of each one of the successive "eco friendly" refrigerants that came out right before the prior refrigerant's patent expired, you'll understand how big of a crock of shiite the whole refrigerant scheme is. It's not about being environmentally friendly, it's about maximizing profits.

 

Is the expiring-patent scenario true of the compounds used in home air conditioning too?

I have an R410 system which now needs repairs and the company is twisting my arm to replace the entire system because "R410 has been replaced by a newer refrigerant"

BTW, I'm sure everyone knows Freon is the brand name for R12 ... excuse me while I get a "Coke" and a "Kleenex" ... ;-)

 

Possibly another reason they tried CO2 / R744 ? Guessing there is no patent on that, haha.