Ok so on my trip to Florida a month or two ago my ac froze up and was found to be low on refrigerant they refiled it and looked for leaks and found none. And my ac was now working fine. Then two weeks ago we had a hot day and my AC felt off but it was not so bad so i just put the windows down and ignored it. Then it was warm again the last few days and the ac seemed fine. Ok so today on the way home from work i noticed that i was hot and the car was blowing hot air at me. So i get home and have my dad look we start the car open the hood and like 20 seconds later it blows what we assume is refrigerant at us. It blows out for like 20 seconds we cut the car off. Turn it back on and the ac is now cold. So there is dye everywhere but it won't do it again. The EC light has never come on so it is not that but we have no clue.

I figure it is either the compressor or a sensor but besides buying the sensor and throwing parts at it don't think that is a good way to proceed. Any help would be great

 

Maybe they put to much pressure in the system and it released it?
Have the system pressure checked again. To much or to little R134 will cause problems.
In fact I am baffeled that it would even work if the system was low as you stated before. On most cars the compressor will not come on at all if it senses a low pressure situation.

We had our first day near 80 today and it seems my A/C is not working either. It worked last summer no problem so I will check the pressure and try adding R134a into the system if it's needed. I hope that fixes it... I don't need anymore repair bills for a while.

 

I was also thinking to much pressure but don't think it would blow and then stop unless they have a pressure release valve? Does any one know if they have one?

 

Never seen one that didn't. Maybe you blew out a seal?

 

I hope not decided to just take it in. I don't have the patience to work on it right now. Work is killing me so i don't need stress at home and while driving to work lol

They said they could look at it Wednesday so hopefully it is something small and not the $420 compressor or something like that.
I would still love to here ideas if anyone has any and of course i will keep you updated as long as the bill does not kill me lol
I am trying a Mercedes only shop that has been working on Mercedes only for 20 + years and has only positive reviews about quality of work and prices so we shall see.

 

So it is the Compressor
So my dad and i are going to replace it that should be fun. So for a few weeks my car will be sitting I need to come up with a parts list and get everything ordered to get my car going again.

 

That sux bro.
Why can't you drive it till the parts come in?
Just use your 5/75 air conditioning?
What else besides the compressor need replacing?
Did they evacuate the system while it was there?

 

Oh noes! That is very strange.. A/C failure is one of my biggest fears, third only to engine or transmission failure. Every time I turn the A/C on in my car, I am thankful that it works - this board has made me super paranoid about the A/C compressor and alternator in my car.

 

I'm currently having AC troubles of my own. Just changed the compressor yesterday and now there is this "blowing" sound that goes loud then silent and then loud and silent again.. Definitely not my blower though since the air is stable. And the AC is not as cold as it used to be..

 

The A/C compressor is waaaaay down on my list compared to the engine or transmission (transmission in my C240 was $3000 at an indie mech last year). I am going to attempt to recharge my A/C system soon since I just found it is uber-weak right now. I have done many other cars, this will be the first time on a Benz. Wish me luck!

 

Good luck star rider!

 

I could drive it but with no ac, still leaking out r134a and spraying my engine bay with dye to try and find what was leaking i would rather park it till it gets fixed. i wonder where it was leaking hopefully it was the compressor and not somewhere else

 

I am trying to confirm a compressor leak. Has anyone used a UV light detector to check for leaks? I am thinking of getting this kit from amazon:




The light detector connects to the car battery. Is this safe to do knowing how sensitive the electrical system is ?

 

Never turn my a/c off, do it with all my cars...just adjust the temp to suit. Never had a problem with any car I have owned using this method...keep 'em running!

 

Yes ~ this is less of an issue with modern swash plate compressors but frequent exercise does more good than harm.

 

but can I connect the UV light to the battery without causing any electrical issues?

 

The best method to determine the amount of Freon in your system is to evacuate the system, do the vacuum hold test the refill with the proper amount of Freon, just adding more Freon to a system without knowing just how much is in there in the first place is a total waste of time and money and could also damage the system.

 

Glyn,

Does the the compressor swash plate always rotate with the pulley even when the AC is in the off position?
What would happen if the compressor stopped working, would it result in a broken serpentine belt and cause other damage (water pump, alternator, etc..)?

Also is there a shorter belt I can install to bypass the compressor?
Thanks.

 

The compressor always rotates, yes. If the compressor stops working it will not break the belt, this happened to my 05. Now if the alternator sprag bearing goes out, it will take out the A/C compressor. Just a note.