dvyce

Guys I am loosing my head here. I have a 2010 c63 and while idling a few weeks back my AC gradually stopped cooling. Fan was still running however it was not cold. I also noticed my Rad fan in the engine was running much higher than normal. I drove the car home with the windows down but could still hear the fan spooling much higher than normal even though my AC was off.

A tech the next day told me I had a bad compressor and so I ordered a new one and had it replaced but to know avail. Now he says its probably my thermostat. The car only has 13k miles on it and I hate to think all of a sudden I have all these things failing at the same time.

After a cold start and the idle settles about after 15 secs, my Fan's speed increases and remains that way even when i go for a drive. I am sure if I can figure this out I could sort out the AC issue.

Any help? Thanks

Critter

Was the system reset after recharging the AC, after replacing and recharge I had to go to Benz Indy shop and he reset something with A Star unit or something similar and the AC worked fine after that. These cars' engineers can be so smart but also so dumb complicated.

dvyce

I do not believe it was reset however when the compressor was replaced it did start cooling when the freeon was added but after about 5mins it stopped again and so I dont think it has to do with that. Also note that I don't have any error indicators lit on my cluster. The engine fan was still running very high which baffled me. Thanks for responding mate

ZephyrAMG

Can you check the compressor? It's most likely a bad compressor, this will be pumping the cold air in...

Critter

Mine after vacuum and recharge with the new compressor it still did not blow cold, but after the reset everything was fine. An AMG compressor runs continuous even when deselected for AC so there is no clutch engaging and disengaging. Mine showed no light on the cluster when the compressor was pooched just warm air.
Go for reset.

The compressor you replaced was it a new Denso unit and did the tech actually put the correct amount of oil into the system along with the right amount of Freon?

roadtalontsi

whos actually doing the work? did they replace the drier too? 13k miles is very low for the compressor to be failing. sounds like you've got a refridgerant leak, hence the worked for 5 minutes then not anymore.

otakki

My car's AC was also problematic a month ago and it was discovered the collision shop didn't charge the correct amount of refrigerant. The amount has to be exact. Either too high or too low would cause the system to work incorrectly. In my case, the fan was also running higher trying to bring the temp down, but the blown air was just not cold. Make sure there is no leak somewhere in the system.

dvyce

My fan runs high. Do u guys know what psi the refrigerant gauge should read?

Merc63

What's your engine temp at?

Critter

2 choices, take it back to the guy who installed the compressor and dryer hopefully and get him to hook up his AC machine to verify there is Freon in the system. The amount he should have added is on the inside of the hood. Also oil should have been introduced while he was adding the Freon, as long as he did this. Also how long did the tech hold the system under vacuum, this would determine if in fact the system had a leak.

Last choice is dealer for diagnostic on system controls, sorry :{

The guys above have good ideas too, leak, not enough Freon, too much Freon.
Just for curiosity have you tried different setups on the controls, max air and just AC on and lower the temps, then start the car? But between the two options you will surely figure it out.
I am leaning to leak at one of the connection points when the tech worked on your car, but have him hook it back up to verify previous Freon load is still there.

Good luck on you project today.

dvyce

From what I know, only the compressor was changed, I don't even know what a dryer or oil is. What oil are you refer to and how is it applied? According to the tests done, I don't have a leak. My car is a 2010 with a kleenman stage 5 build and only 13k on the clock. I am now being told it could be my thermostat. Frankly I am soo ticked off I am ready to sell. I don't trust these tech guys here in Ghana so I do not want these chaps faffing around. I just got to south Africa and will be heading to Mauritius tomorrow so hoping to have this sorted by next week when I get back. I just don't understand why my engine fan will be spooling at that high speed. And btw my car is not overheating. Temp reads just over the half mark and it sounds and runs great apart from the noisey fan and no cooling.

Critter

The AC dryer is a cylindrical tube mounted under the rad, this is changed whenever the AC system is opened up, this tube is hooked into the AC tubing to remove moisture that would be introduced when the system was opened up to replace the compressor. The oil is refrigerant oil to lubricate the compressor, a new comp would only have a small amount in it for assembly and there is a required amount to ensure proper lubrication of the AC compressor. There is a electrical connection coming out of the compressor, you might want to ensure this is fastened firmly, also follow any ac line just in case one of the electrical connections is not in place.
To replace the AC compressor, the fan must be removed to gain room, wondering if by chance there is an issue with the fan controller, personally I would use a good flashlight looking into the area behind the fan for good connection or wiring not in place. Anywhere on the front of the engine look for good connections or wiring not correct, bare or stretched.

Like it was mentioned before, a low Freon load will not produce good results. If the fan spools up when the ac is not selected then possible damaged controller when the tech removed it.
Search on this site for access to the "ac system check"/diagnosis which shows numbers on the command center, I believe #7 is the ac Freon amount, but the other values are checks for the AC system, maybe something will show there.

As I stated before my car I had the Freon removed, then changed the comp+dryer, vacuumed the system, recharged with proper amount then had to get a reset to tell the car whatever, then the AC blew cold.

Woww sorry for the verbiage, but it was all on one breath. LOL

Mbaws63

i have the same problem.... sometimes the Ac wroks and sometimes it does not. But i have relized when I first tsrat the car i lower the fan and it works, but if i start the car and blast the AC i dont get cold air.

dvyce

Guys on the real, I have been so caught up about my issues and not taken time to thank you all for your support. Thanks a ton for all the time you guys have taken to try and assist with my baggage. I am sending all this to my tech now and part of my problem is that I don't have that many certified techs around and all seem to be jacks of trades and masters of none. TIA (this is Africa). I'll send all this to my tech now so he is ready once I am back from holiday next week.

roadtalontsi

a/c pressures will obviously vary but approximation at full load.... low side 25-40psi high side is ambient temp x3 = or - 20 psi. so if its 100* outside your looking for 280-320psi (100x3 = 300 +/- 20 = 280/320. If you fan just automatically blasting 100% even with the a/c off and car cold there is a good chance of some communication issue between the m.e. (engine ecu) and the front sam for the fan signal. its default is full blast if no signal is received. Also keep in mind your Kleemann tune could have adjusted some parameters on it? not sure if the a/c just quit or if it happened when upgrading.