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BLUF: I'm back with the trouble. My A/C has been working fine, but then the other day I got into the car and noticed it was blowing air that seems to be piped in directly from the deserts of Mexico.
Symptoms: If I put the climate to LO (all the way down) and leave it on SYNC (both sides have the same value) with all other settings on AUTO (this includes the A/C being on), the blower fan goes to max (as does the fan under the hood) and no matter how long the car is left like that, it blows hot air. This also persists even while driving the car. As a result of this I have been driving largely with the climate just turned off and using the backup 4/40 aircon system. Even in this setup, the cooling fan on the engine seems to run at maximum speed quite frequently, only turning off when the engine stops during start/stop operations and spooling back up shortly after restart. The engine temperature gauge does not ever rise above the halfway mark, and the car doesn't seem hotter than usual (except inside the cabin).
What I've done: Read all codes with an OBD-II scanner (not a Mercedes specific one, though, so take that with whatever salt you desire) and found zero stored codes. Other than that, not much, really. I don't know what refrigerant/freon this has (see below) and therefore have not used a cheap A/C recharge kit because the only available ones around are R134a and I don't know if that's right. I also certainly don't want to combine freons.
The Freon Debacle: I cannot tell if this has R744, R1234yf, or R134a. I have access to WIS/ASRA and it gives me this info, found in the safety information sheets listed on AR83.30-P-1760LW (Drain, evacuate, and recharge air conditioning, check for proper operation and check for leaks) E300 Air Conditioner Drain Evac Recharge.pdf:
- Models 205, 213, 253 with code 2U8 (alternative refrigerant) would have R1234yf
- Model 213 with code 1U6 would have R744
- Models 205, 253 without code 2U8 have R134a
- Model 213 except code 1U6 and except code 2U8 have R134a.
That info would lead me to believe that my car (which when the VIN is decoded on https://lastvin.com does not have code 1U6 OR code 2U8) has R134a - in which case this is a trivial matter that I could fix for $30 at the auto parts store. But if I am missing something and this has the 100-Bar R744 system, which from everything I can find online was fitted to all E-Class sedans starting in late-2016 and early-2017, it would be rather unhelpful (and probably, in the end, more costly) to put R134a in a system not designed for it. I also found this website: https://bads.lt/en/blog/technical-in...34a-and-1234yf which is apparently from Latvia but lists all the different refrigerants/freons that are to be used for various Mercedes cars as well as the filling capacities - on this site, it lists the E-Class 213 as using R134a, R1234yf, AND R744, thus confirming the confusion.
What I need: I need someone to tell me what the hell refrigerant this thing uses, and if it's best to drive around in sweat until the dealer can look at it or if I'm safe to use the local auto parts store's A/C recharge to try to troubleshoot, or if there are other steps I should take before I hook a pressure gauge up to it to find out if this problem is even low refrigerant.
And thus I submit my prayer to the Mercedes forum gods. Thanks for reading!
Last edited by ArchAngel2190; Yesterday at 10:46 AM.
Reason: Did not graduate Derek Zoolander Center For Kids Who Can't Read Good
I would try a decent diagnosis first as fan running at max speed means a lot. A broken wire from pressure sensor, a missing temperature sensor or anything else.
No need of pressure gauge if you find a a way to properly connect to the car with a diag system.
About gas type, you have a sticker under the hood with all needed informations.
First advice with these AC systems, please, do NOT attempt to recharge these systems w/o first emptying completely, vacuum it, and charged Exactly as indicated in the label under the hood. That label should state refrigerant type, and exact weight required.
Without your AC compressor part/model number, I cannot tell if yours has a magnetic clutch or not. My W212, and W166 do, but the W211 does not. It is engine type, and platform dependent. Picture?
Owning an MB-aware bi-directional scanner, either third party or XEntry clone will pay for itself quickly.
Scan for codes, watch for live data. Post it and forum members will guide you
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
You need to have the problem properly diagnosed and not guess at stuff. A/C systems can be complicated and have many reasons for not working. If you don’t know what you are doing, you could do more damage to your car or even break some serious laws.
I recommend using XENTRY and follow the troubleshooting steps. I also recommend joining BenzNinja and have a professional help diagnose your problems.
I would try a decent diagnosis first as fan running at max speed means a lot. A broken wire from pressure sensor, a missing temperature sensor or anything else.
No need of pressure gauge if you find a a way to properly connect to the car with a diag system.
About gas type, you have a sticker under the hood with all needed informations.
I do have WIS/ASRA but none of the diag tools... hence the trips to the dealer, sadly. I will take a look for the refrigerant sticker, where exactly would it be?
Originally Posted by juanmor40
First advice with these AC systems, please, do NOT attempt to recharge these systems w/o first emptying completely, vacuum it, and charged Exactly as indicated in the label under the hood. That label should state refrigerant type, and exact weight required.
Without your AC compressor part/model number, I cannot tell if yours has a magnetic clutch or not. My W212, and W166 do, but the W211 does not. It is engine type, and platform dependent. Picture?
Owning an MB-aware bi-directional scanner, either third party or XEntry clone will pay for itself quickly.
Scan for codes, watch for live data. Post it and forum members will guide you
I have always toyed with the idea of getting a Xentry or Xentry clone, but I don't own a windows laptop, which makes getting a working version rather a moot point until I source a win laptop first. Perhaps I will try to source a second-hand Toughbook or something of the sort, but as I understand it, Xentry wants XP or 7, not 10 or 11... I do know that the compressor is engaging, though I forgot to include that in the initial post. Just did a regular "engage AC and watch/listen for clutch" and can confirm it does engage.
Originally Posted by JettaRed
You need to have the problem properly diagnosed and not guess at stuff. A/C systems can be complicated and have many reasons for not working. If you don’t know what you are doing, you could do more damage to your car or even break some serious laws.
I recommend using XENTRY and follow the troubleshooting steps. I also recommend joining BenzNinja and have a professional help diagnose your problems.
Yes, I am aware of the ramifications of doing stupid stuff... that's why I consulted the forums BEFORE I actually touched anything. Now I know to look for the sticker to tell me about refrigerant types. As I said above, I don't have Xentry yet as it's pricey and I lack the hardware. Sourcing that can be done in time but not in a day, so I have to resort to old-fashioned mechanic-ing to determine problems as they arise, without the use of MB-specific diag tools that I do not have. I'll look at BenzNinja but the really obnoxious emoji-laden, photo-filled post they made just two below mine is kind of turning me off, and I would rather own than rent... are they really worth it?
You can get XEntry clone and all the supporting tools, DTS, Vediamo, WiS/ASRA, EPC on Windows 10/11 these days.
anything with XP, Win7 is for the older versions which may be useful for certain "use case".
I do have WIS/ASRA but none of the diag tools... hence the trips to the dealer, sadly. I will take a look for the refrigerant sticker, where exactly would it be?
I have always toyed with the idea of getting a Xentry or Xentry clone, but I don't own a windows laptop, which makes getting a working version rather a moot point until I source a win laptop first. Perhaps I will try to source a second-hand Toughbook or something of the sort, but as I understand it, Xentry wants XP or 7, not 10 or 11... I do know that the compressor is engaging, though I forgot to include that in the initial post. Just did a regular "engage AC and watch/listen for clutch" and can confirm it does engage.
Yes, I am aware of the ramifications of doing stupid stuff... that's why I consulted the forums BEFORE I actually touched anything. Now I know to look for the sticker to tell me about refrigerant types. As I said above, I don't have Xentry yet as it's pricey and I lack the hardware. Sourcing that can be done in time but not in a day, so I have to resort to old-fashioned mechanic-ing to determine problems as they arise, without the use of MB-specific diag tools that I do not have. I'll look at BenzNinja but the really obnoxious emoji-laden, photo-filled post they made just two below mine is kind of turning me off, and I would rather own than rent... are they really worth it?
You can install Xentry for any cheap Passthru interface into a virtual machine on your MAC
You can get XEntry clone and all the supporting tools, DTS, Vediamo, WiS/ASRA, EPC on Windows 10/11 these days.
anything with XP, Win7 is for the older versions which may be useful for certain "use case".
I'm thinking I might buy the YOUCANIC scanner I've seen online... it's cheaper than most of the similar ones and doesn't require that I pay extra for certain vehicles, it's bi-directional, and it will do what I need it to do for the most part. Large/intensive repairs are the purview of my dealer, I just don't want to have to take the thing there for every little thing.
Originally Posted by trigital
You can install Xentry for any cheap Passthru interface into a virtual machine on your MAC
I've not had luck with Wine/CrossOver... I've thought about putting it in a virtual machine though but my Macbook Air lacks RAM and SSD space for that. :/
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
This renewed ThinkPad will work perfectly. @BenzNinja provides an SSD with Windows 10 and all the software installed. He then connects remotely and configures the software to run for you. Setting XENTRY up and licensed properly can be complicated. He does it all for you. The license keys are specific to your hardware and sometimes they may get corrupted. If that happens, no problem. BenzNinja will connect in and restore everything. I've run the gambit on XENTRY, WIS/ASRA, and EPC gotten from Asian vendors, and BenzNinja's software has been the most stable and reliable that I have used. He also doesn't use workarounds to get the software working that sets off anti-virus software. Besides the software, you get diagnostic support from someone who thoroughly knows what he is doing.
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
Originally Posted by ArchAngel2190
Yes, I am aware of the ramifications of doing stupid stuff... that's why I consulted the forums BEFORE I actually touched anything. Now I know to look for the sticker to tell me about refrigerant types. As I said above, I don't have Xentry yet as it's pricey and I lack the hardware. Sourcing that can be done in time but not in a day, so I have to resort to old-fashioned mechanic-ing to determine problems as they arise, without the use of MB-specific diag tools that I do not have. I'll look at BenzNinja but the really obnoxious emoji-laden, photo-filled post they made just two below mine is kind of turning me off, and I would rather own than rent... are they really worth it?
Before you start adding refrigerant, you need to ensure you are low. If you are, you need to know why. I found the Schrader valve had a leak on my truck and it was losing refrigerant.
The minimum set of tools you need are a set of gauges, a vacuum machine, and a way to recover refrigerant that you evacuate. On the sticker, you will see the type of refrigerant and the amount to add to an empty system. This is the stick on my 2015 SL400. It's right in front. My car uses 550g +/- 10g of R-134a.
Before you start adding refrigerant, you need to ensure you are low. If you are, you need to know why. I found the Schrader valve had a leak on my truck and it was losing refrigerant.
The minimum set of tools you need are a set of gauges, a vacuum machine, and a way to recover refrigerant that you evacuate. On the sticker, you will see the type of refrigerant and the amount to add to an empty system. This is the stick on my 2015 SL400. It's right in front. My car uses 550g +/- 10g of R-134a.
To complement your suggestion, I take the car to a mechanic with AC service, they evacuate the system, and credit me for the amount taken. I do whatever I need to do in my car, AC or else, return for the recharge and they charged me $120 + extra refrigerant added to reach the value on the label if missing.
I do have my own set of gauges now, but when away from home and helping others, I rent the gauges and vacuum pump from AutoZone, put a deposit that gets refunded when I return the tools. Basically, no cost for tooling. It has worked for me.
and I do still having an independent I trust, but sometimes I want to do it myself (time permitting and within my comfort zone)
I do have WIS/ASRA but none of the diag tools... hence the trips to the dealer, sadly. I will take a look for the refrigerant sticker, where exactly would it be?
I have always toyed with the idea of getting a Xentry or Xentry clone, but I don't own a windows laptop, which makes getting a working version rather a moot point until I source a win laptop first. Perhaps I will try to source a second-hand Toughbook or something of the sort, but as I understand it, Xentry wants XP or 7, not 10 or 11... I do know that the compressor is engaging, though I forgot to include that in the initial post. Just did a regular "engage AC and watch/listen for clutch" and can confirm it does engage.
Yes, I am aware of the ramifications of doing stupid stuff... that's why I consulted the forums BEFORE I actually touched anything. Now I know to look for the sticker to tell me about refrigerant types. As I said above, I don't have Xentry yet as it's pricey and I lack the hardware. Sourcing that can be done in time but not in a day, so I have to resort to old-fashioned mechanic-ing to determine problems as they arise, without the use of MB-specific diag tools that I do not have. I'll look at BenzNinja but the really obnoxious emoji-laden, photo-filled post they made just two below mine is kind of turning me off, and I would rather own than rent... are they really worth it?
I worth it as you don't even paying the membership
You get your car repaired
lifetime warranty
Lifetime free repair help, repair coding and flashing
+ you get your car mods for free
Laptop is $100 from ebay
No virus nor trojans
so instead of going the cheapo path with tons of problems....
9029084[/url]]Before you start adding refrigerant, you need to ensure you are low. If you are, you need to know why. I found the Schrader valve had a leak on my truck and it was losing refrigerant.
The minimum set of tools you need are a set of gauges, a vacuum machine, and a way to recover refrigerant that you evacuate. On the sticker, you will see the type of refrigerant and the amount to add to an empty system. This is the stick on my 2015 SL400. It's right in front. My car uses 550g +/- 10g of R-134a.
Alrighty, thanks to the suggestions here I was able to confirm I do in fact have R134a. So, that takes the g-whiz CO2 and R1234yf refrigerants out of the equation. Now I can begin to troubleshoot - I know the compressor is engaging. I know the blower motor is working. I also notice the fan under the hood spinning at max RPM all the time, which I wonder if this could be due to the fact that the refrigerant is low and so it’s trying to force the condenser to condense when there isn’t anything (or enough) to condense… just a hunch.
This thread has derailed and devolved into a discussion about how I can’t diagnose or repair anything without an expensive diagnostic solution, and which one is best. Knowing that I do not presently have a diag solution, and knowing that even if I buy one tomorrow it won’t be here the next day, I’m hoping that I can solve this issue without the help of a computer. Tomorrow I will throw a pressure gauge on the low pressure side and test to see what it’s at - if it’s low, I’ll add R134a and report results. If it’s not, I won’t add anything, and will report back again.
In all cases, I already had an appointment on the 16th for a state inspection, so if it isn’t fixed by then, I will have the dealer look at it and, again, will report back with results.
Thanks to everyone who has provided suggestions on both refrigerants and diagnostic solutions!
Alrighty, thanks to the suggestions here I was able to confirm I do in fact have R134a. So, that takes the g-whiz CO2 and R1234yf refrigerants out of the equation. Now I can begin to troubleshoot - I know the compressor is engaging. I know the blower motor is working. I also notice the fan under the hood spinning at max RPM all the time, which I wonder if this could be due to the fact that the refrigerant is low and so it’s trying to force the condenser to condense when there isn’t anything (or enough) to condense… just a hunch.
This thread has derailed and devolved into a discussion about how I can’t diagnose or repair anything without an expensive diagnostic solution, and which one is best. Knowing that I do not presently have a diag solution, and knowing that even if I buy one tomorrow it won’t be here the next day, I’m hoping that I can solve this issue without the help of a computer. Tomorrow I will throw a pressure gauge on the low pressure side and test to see what it’s at - if it’s low, I’ll add R134a and report results. If it’s not, I won’t add anything, and will report back again.
In all cases, I already had an appointment on the 16th for a state inspection, so if it isn’t fixed by then, I will have the dealer look at it and, again, will report back with results.
Thanks to everyone who has provided suggestions on both refrigerants and diagnostic solutions!
Engine fan will never blow at maximum when the A/C system has low pressure. This is why I already told you to start from electronics. The fan role is to lower the temp (...) this way the pressure ( the risky parameter inside the engine compartment ) will remain LOW. If the pressure is too high or wrongly interpreted as too high because faulty pressure sensor, wires, connectors or AC ECU then the fan will be at maximum.
Also the fan could be defective as well, if with AC Off still blow at maximum.
I’ll have to grab some gauges as somehow the shop doesn’t have any yet… clearly we have yet to deal with a lot of A/C issues.
Originally Posted by trigital
Engine fan will never blow at maximum when the A/C system has low pressure. This is why I already told you to start from electronics. The fan role is to lower the temp (...) this way the pressure ( the risky parameter inside the engine compartment ) will remain LOW. If the pressure is too high or wrongly interpreted as too high because faulty pressure sensor, wires, connectors or AC ECU then the fan will be at maximum.
Also the fan could be defective as well, if with AC Off still blow at maximum.
The fan still blows the same when the entire climate system is off, as I described above, which leads me to believe that it might be thermostat related even… if that’s the case would the car disable the A/C system without any lights on the dash/flashing A/C light in order to preserve cooling? Just a theory…
Also, as a general update, I went to the auto parts store today to buy an A/C recharge kit and was informed that my state has banned the sale of R134a because it’s bad for the environment… which is ironic because now I have to drive to the next state over if I need it, which, coincidentally, is also bad for the environment…
Yesterday, 10:42 AM
