Going to try my luck with this DIY tomorrow... A/c compressor and all. Wish me luck, MB fam!

 

Hi, I'd like your input on whether I'm shot or not on a brand new compressor I just had replaced. I trusted a mechanic instead of going DIY and the guy clearly didn't know what he was doing. Bought a whole kit from buyautoparts.com and the mechanic didn't use anything besides the compressor and lubricant. When I asked why he didn't replace the accumulator dryer he said it was because this car didn't take that part. And since I had no idea where that was located and it wasn't readily visible I had to accept it for the moment but thank you for sharing the information as to where that is located. I can now clearly see it and I will go back and have them replace it as well as do a system flush. Hopefully my compressor can still be saved before there is greater damage. I just bought this Mercedes and the previous owner said that a year ago it was blowing cold but suddenly started blowing hot just like someone on the forum previsously mentioned. I still don't know where the expansion valve goes or the orifice that looks like a filter which seems to be rather large if that is in fact the orifice. This part is blue and has a section that has little Styrofoam *****.

 

http://www.mercedestechstore.com/pdf...2010-30-02.pdf
see page 29

BTW, is it a grinding or more like a chirping sound you hear? How old is your alternator pulley?

 

Hi thank you for the diagram reference. They are super helpful.
It's not so much a sound that concerns me but it is definitely grinding, not chirping. I'm not sure how old the alternator pulley is because ive only owned the car for one month. The compressor still works and blows cold and I try to only use it while I'm actually traveling steady because the problem is when I come to a stop that it makes the engine shake terribly almost as if the motor mounts were bad but I know they're not because they were fine before the replacement even with the fan on full blast. The engine shaking caused by the compressor even lasts a few minutes after I turn off the ac.

 

The compressor does not turn off instantly when you turn off ac. Try turning the fan speed to zero with auto mode disabled, then the compressor should turn off almost instantly.

Well, with grinding only when ac is engaged, I would guess that it is still something to do with the drive belt system. You should be able to see the belt shaking/tensioner jumping violently.

 

Any tips or tricks on getting the bolts out? My compressor is making a WHINE noise and I'm 100% positive that it's coming from the clutch/pulley.

Thanks much,
-Nigel

 

I am pretty sure I saw a procedure on replacing the dampers inside the AC pulley.
What I am not sure of is which chassis it was applicable to

My compressor also whines, but I decided to live with it so far...

UPD: This is pretty similar to what we have in our cars: http://www.bimmerfest.com/forums/sho...d.php?t=646025

 

My Mercedes dealer told me I needed a new a/c compressor because mine has a slow leak. They told me it would be $1400 to replace it but they also told me that many times the a/c condensor can break when they do this. is this really true? they told me since they were Mercedes and knew how to do this, the condensor would probably be alright but if needed to be replaced, it would cost another $795! ouch! does their explanation seem right and honest? should i get a second opinion and how do I do that?

Thank you,
David

 

Is that labor included with the compressor? Or that is JUST the compressor?

I replaced my compressor with a new OEM one on amazon for $200 shipped prime. The condensor can also be found on amazon OEM for roughly $80-90 shipped prime. The only time I think the condensor would break is if they aren't careful. I DO know the top threads of the condensor cap were stripped/cross threaded because of the idiot shop who touched it but other than that there is really nothing to break on it short of puncturing it or breaking off a connection...

I'd definitely go to another place for another opinion. Unless there is metal in the system then you most definitely will want to replace the condensor but if you are good with a wrench it's not a hard job at all. It's more tight in certain places but it took me about a weekend to replace the compressor and condensor while I was doing other things. Vacuum the system then fill with r134a.

I think total repair for my AC was $360, which included the new compressor, pag oil, condensor, and r134 gas. I'm sure it would have approached the $2k mark had I had a shop work on it or took it to a dealer...

-Nigel

 

Im going to go on a limb here. I am almost certain you can do this without removing the coolant hose, front crossmember, and radiator baffle, fan. I have removed those parts before just to replace the baffle.

Not trying to go against OP, but I am trying to minimize removal of parts that might scare off the DIY'er.

Yes If you are replacing the compressor, you should replace the drier(desiccant), and while your at it expansion valve and also any o-rings associated with these parts.

 

thank you both for your prompt answers. yes, the price does include labor. i have to admit that i need an owners manual to change a light bulb so the thought of my doing this myself has never entered my mind. but i just needed to know about the condenser part of the equation. i don't know what one has to do with the other but i really value your input about it. i'll just have to bite the bullet and pay for it at mercedes. i really like my dealer and my car has never been serviced anywhere else since i bought it brand new. but this time, i have a new service rep and i wasn't sure about his evaluation.

thank you again,
david

 

I did this job about 2 years ago on my 2002 C240. Parts I replaced were: AC compressor (Denso 471-1474), Expansion Valve, Receiver drier insert, 8 oz. bottle of PAG 46 oil and an O-ring kit. Had my neighbor mechanic evacuate the AC system and re-charge after I replace parts mentioned. As NewShockerGuy mentioned, all parts cost me close to $400. I didn't have to remove my fan or any parts off the front of engine. Removed the AC compressor out from the top in between the engine & fan & radiator. Took me about 4 hours to do the job.
If you're comfortable doing the work, definitely get a price from another shop that does AC. Good luck.

 

When you changed your drier/dryer did you add oil to the desiccant? If so how much oil did you add if you remember?

 

Nope not at all. I put all oil in the compressor. It DOES tell you that if you are replacing the desiccant that you need to add more oil... I want to day I did 6oz... I'd have to look through all my stuff but I believe that was the number of oz I used.

-Nigel

 

Whats up Forum.

I just removed the compressor after following this guide and am wondering if I could rebuild it myself........ the clutch spins freely on mine.

When it was on the car, and it was moving, the air cooled a fraction of a percentage.

What should I do next?

 

Well you are too late now, before taking the system apart first you have to find out the problem----to do that you place AC gages on the system and read the data---the high side should be 15-17 bar----what was yours?

What to do next--put the compressor back refil and test!!

 

I forgot to mention that I had an MBZ tech with an SDConnect computer try to engage the clutch and he couldn't. But I turn it with my hand and it turns freely.

 

Hello you add 8oz of pag 46 to the compressor. Your ac still working fine. I on the middle of this job and I don't know exactly bow many oz of oil on the compressor

 

I think my compressor is up for replacement ... pulley isn't completely silent when turning, and very slight play in it.

I drove the car on ramps, took off the front engine cover, and confirmed that I can reach all three torx bolts pretty easily from underneath with wobble and U-joint socket extension.

Fyi I don't think you have to drain coolant or take out the fan ... this video does it without: (albeit this video removes the airbox and intake manifold, which I think is unnecessary.)

There is also an electrical connector that sits on the top side of the compressor. I assume this is easy to remove once the unit is unmounted and the hose connections are out?

Q: I then have a question about driving with the system empty. I was thinking of driving the car down to an AC shop, having them empty out the system, then I would drive it home, replace the compressor, drive it back to the AC shop to have them vacuum out and fill the system. Can I do this? If so, do I need to put oil in the new compressor before install it because I will be running the pulley with no AC?



Thanks. John

 

I am looking at doing the same thing.
My current thoughts are to fit the non-A/C drive belt, 7PK2315, so the A/C compressor is not driven.

 

You can remove the hub from the AC pulley (there is no clutch) and that will allow the pulley to spin without turning the compressor.

I just replaced the seized compressor on my c320. The job was simple. Remove the belt tensioner and drop the front sway bar for access. Undo the 13mm bolt at bottom of the driver side engine mount so I can Jack up the engine a bit for easier access to the rear bolt. Then removed the suction hose from the car, unplug the compressor and remove the 3 bolts. The compressor cones out the top. If your car needs engine mounts this is the time to do then because with the compressor out of the way you won't have to drop the exhaust. The replacing compressor was a $140 rebuilt off of eBay with a 1 year warranty pluz 8oz of pag 46 oil with dye. Ice cold AC is a beautiful thing.
https://i.imgur.com/fNmHi9y.jpg

https://i.imgur.com/MWzzBBa.jpg

 

I would do what tjts1 said. I replace my AC compressor 4 years ago with a Denso unit (#471-1474). I also replaced my expansion Valve, Receiver drier, 8 oz. bottle of PAG 46 oil and new O-rings.
Reason for replacing my AC compressor was that a seal (front) had gone on my AC compressor unit and started leaking the "PAG 46" oil out. Over time the compressor motor eventually failed (seized).
When the oil slowly leaked out, my serpentine belt had this very light oily coating on it and the surrounding areas. I always thought it was my PS pump that had the small leak, but PS fluid level was never low and never had to be topped off.

 

I have the same problem, yesterday night while waiting for car park for about 45 minutes
my car c200k did not give out cold air, when I was parking my car, the steering was very
heavy, inspection reveal that one drive belt was snapped.
Today, I installed one new belt, the car was running well, but I turned the air conditioner, there was no cold air coming out, I hear some noise coming from the A/C compressor, I hoped I could learn from you to repair it well. Thank you.

 

Fyi I dropped by a local Mercedes mechanic last week and asked about driving the car without refrigerant in it. He said the new compressors will generally come with oil, and as long as there is oil in the compressor then you can drive the car with the belt on (you just won't get any cold air).

 

Thank you, very helpful info. But I can't see the pictures, am I doing something wrong? I just purchased a Denso compressor for my 06 SL 500 I am hoping to do the job myself.