Sounds Expensive! - PeachParts Mercedes-Benz Forum

Lord Hemming · #1 11-18-2007, 08:11 PM

I noticed a bearing kind of noise when out driving today. When I switched the A/C to ECON the noise stopped. When I switched the A/C back to normal mode the noise started again. The A/C is still ice cold, it just sounds like the condenser (is that the only moving part?) is on it's way out.

Any idea what the cost of replacement would be assuming my diagnosis is correct?

Alkraut · #2 11-18-2007, 08:54 PM

Might be a slipping belt to the compressor, easy fix. Check to see if all belts are tight. Or, it might be a bearing in the compressor, or an internal compressor problem. A rebuilt compressor is in the $500 range. You should have an AC shop do the diagnosis and repair. They may have an evacuation, recovery and recharge system for the Freon R12. R12 is very expensive. If not, you will have to consider a conversion to R134. Shop around for a good AC place that can still service Freon and compare costs. Total repair cost could be in the $900-1200 range with labor. Your condensor has no moving parts.

Lord Hemming · #3 11-18-2007, 09:17 PM

It's not the belts, they are all new and the noise is a bearing humming noise if that makes sense.

Not interested in converting the A/C, so I will shop around to see who has the kit in Houston to do a quality repair using R12.

I appreciate the feedback, I was assuming around $1200, but I may go for a new (not rebuilt) condenser and pay the premium for a new part.

aam · #4 11-18-2007, 10:40 PM

Quote:

Originally Posted by Lord Hemming

It's not the belts, they are all new and the noise is a bearing humming noise if that makes sense.

Not interested in converting the A/C, so I will shop around to see who has the kit in Houston to do a quality repair using R12.

I appreciate the feedback, I was assuming around $1200, but I may go for a new (not rebuilt) condenser and pay the premium for a new part.

My friend lets start with the right foot this time.
How long you have the car , year, miles, and model, are we talking.
1) The condenser is the a/c coil seating in front of the radiator.
It's job is to take the heat out of the compressed gas, it has no moving parts. ( No sound ) do not replace.
Unless it is blocked.
2) Now that this is out of the way.
3) On economy the compressor is off. ( No noise )
4) Now back to your your complain when A/C is on, it is normal to hear some noise it is your compressor working.
4) If noise is more then normal, it is passable you may need oil in the system.
You said it is cooling ok, so refrigerant should be ok, and your clutch is not slipping.
Also check the belt tensioner, if you have one.
With out more info. I can't help you further.
Regards.
aam.

Lord Hemming · #5 11-18-2007, 11:53 PM

aam,

Here are the answers to your questions:-

560SL - 1988 32k miles, I have owned the vehicle since September

1) The condenser is the a/c coil seating in front of the radiator.
It's job is to take the heat out of the compressed gas, it has no moving parts. ( No sound ) do not replace.

Agree!

2) Now that this is out of the way.
3) On economy the compressor is off. ( No noise ) correct!

4) Now back to your your complain when A/C is on, it is normal to hear some noise it is your compressor working. But this is a wurr noise you can hear in the car, it's not the usual 'asmatic' noise you hear when the A/C is working!

4) If noise is more then normal, it is passable you may need oil in the system. OK, sounds like this could be an option, the dealer said they had serviced the A/C with freon etc. but maybe they didn't oil it
You said it is cooling ok, so refrigerant should be ok, and your clutch is not slipping.
Also check the belt tensioner, if you have one. I am sure it is not the belts, but I will take the car in next week just in case

So it sounds like the compressor, is this serious?

POS · #6 11-19-2007, 08:28 AM

Quote:

Originally Posted by Lord Hemming

So it sounds like the compressor, is this serious?

If the noise can be controlled by turning on and off the compressor, then you're compressor is failing. Yes, there are bearings inside that compressor, and the clutch can fail as well.

It is serious if the bearings are failing. If the internals of the compressor break loose, they'll trash your AC system which makes the job of replacement all the more difficult. And you'll have to replace most everything in that case.

First advice - DON'T TURN ON THE COMPRESSOR.
Second advice - Get it to a mechanic (an honest one, please) and get a second opinion about the noise and its location. It sounds like you'll be buying a new compressor, drier, expansion valve, condensor, and a serious flushing job. My guess - $2000.

donbryce · #7 11-19-2007, 08:55 AM

There's an auxilliary fan mounted in front of the condenser, which could be making a noise like you describe. Worth checking, just listen for when it comes on.....my humble 2 cents

ctaylor738 · #8 11-19-2007, 10:21 PM

Well, if any place would have a good AC shop, it would be Houston. It does seem like 32K miles is a little soon for a compressor to fail. Maybe it needs some freon.

Do keep us posted.

Lord Hemming · #9 11-19-2007, 11:29 PM

POS,

As you're a local, would you know a good shop to use in the Houston area? I picked up my 560 in Utah, so this will be my first local repair.

I would appreciate your advice, I don't want to cause serious damage to the A/C system, so want to get the car to a shop by early next week (at the latest) for a professional opinion and the repair completed before Christmas.

POS · #10 11-20-2007, 08:33 AM

I go to ******** Stuttgart - I first met Hans back in the early 1980s when my father owned a 1971 3.5 and a 1971 280SL. After those Dad bought two SECs; Hans fixed those too. Now I'm into MBs and Hans is working on all my stuff. He's honest, reasonable, and I have no qualms whatsover referring him. He only works on MBs and he's fantastic with the older stuff.

******** Stuttgart
2020 Antoine Dr
(713) 956-0656

You could also try Silvio's which is west of Downtown, or Gus near the Galleria (can't remember the name of the shop, but he's at Schumacher Lane and Chimney Rock).

Lord Hemming · #11 11-20-2007, 03:15 PM

Thank you POS.

I visited ******** lunchtime and Hans said I was paranoid

. The noise from the compressor is 'normal'. I explained where the recomendation came from ( I don't know your name, but he said he knew the AMG SL) so expect a Christmas card!

Good news about the A/C, I will go see Hans when I need an oil change as he seems a good honest guy.

I appreciate the recomendation!

POS · #12 11-20-2007, 04:56 PM

Glad to hear it - the name is Brian Schneider. I have to go see him in the morning anyway, so I'm sure I'll hear about it.

Being paranoid? Sounds like Hans.

aam · #13 11-20-2007, 05:52 PM

Quote:

Originally Posted by Lord Hemming

Thank you POS.

I visited ******** lunchtime and Hans said I was paranoid

. The noise from the compressor is 'normal'. I explained where the recomendation came from ( I don't know your name, but he said he knew the AMG SL) so expect a Christmas card!

Good news about the A/C, I will go see Hans when I need an oil change as he seems a good honest guy.

I appreciate the recomendation!

LOL
Ahhaaaaaa.
Good for you.
This is why I asked how long did you have the car.
New noise, or old noise.
Nothing personal but new owners, often complain about normal noise.
And that is why I never have said to replace the compressor.
You said the car is cool.
If you had bad bearings the refrigerant with time
will leak out = No cooling.
Take car home and if it needs repairs do them there, if you have problems
it is easy to take it back, and complain.
If you have to do repairs on the A/C, do it a little before the summer,
if something goes wrong, usually they will warranty their work.

Regards,
aam.