94 S 500 Air Conditioning Problems again
 

I had a 3 K evaporator job done on my car less than 500 miles ago. This car has only 11000 miles on it! Now the area around the compressor has oily green spots on it. I assume this is from the dye which remains in the R-134 system from the past. Any one have any thoughts on what is gone now? There is no dye on the compressor pully, only spots on the stabilizer bar under the compressor area. Compressor seals? The sensor on the side of the unit? How about costs for a compressor job. Rebuilt or new? Or just a seal job. As the car sat for long periods of time, am I in for more headaches in this area??

This is getting expensive! My extended warranty co. would not pay for the evaporator job because of the dye existing in the system ment that the evaporator was bad prior to their warranted date. I am still fighting that one. I imagine they will pull the same for this repair.

Thanks to All
Mark

How could this be? Some people use OIL that has the dye built in. So, if they replaced the drier, they added oil and hence dye. That is a simple one.

I would think that it is possible that the tech took loose the lines to flush the system and made a mess?

is it not cooling????
 

Mark, you may be crying wolf to early! Maybe it is just some byproduct of the work that was done as Benzmac says.

To check it out, try this: go to my page (www below) and click #14 in the menu. Set your rpm to about 1500prm and monitor numbers 3, 4, 5 (especially #5) and 7.

If #5 cycles between 37F and 43F while #7 cycles from about 10 to 14, go out and have a beer!

reply from Mark via email . . .
 

Thanks Jim,

I did the tests and Test 5 varies between 38-44 while 7 varies between 7-16. The area in question with the green spots is new in the last 2 days (around 200 miles).

I cleaned the entire area up and removed the lower plastic cowl between the front of the car and the engine area and cleaned this also. It beats me how the spots get on the stabilizer bar and you can't see it coming from the compressor itself.

I think I mentioned that 2 days ago I found similar spots on the plastic air duct pipe from the front of the car, drivers side. I cleaned this up and have not seen them here again. It seems like something is spurting freon out under pressure, not aiming the same way all the time.

I am taking the car in to the shop on Monday. What do you think about the compressor replacement/rebuild? Or just seal replacement?

My reply:
From what you measured, it looks like the a/c is working ok! The measurements are typical of what you should see. If they continue to hold, then you do not have a leak!

Re the green stuff: maybe need to monitor your radiator and hose connections. I'm no a/c expert but a/c leaks under pressure won't appear as 'blobs'. They would be more of a 'spurt'. A typical scenario when a compressor leaks is a circular 'band' of oil around the bottom drip pan.

If it's bad, it probably should be replaced rather than rebuilt. But in your case (only 11K miles), maybe the seals way is better. But I wouldn't do anything until you are really sure it's bad.

One of the best diagnostic characteristics of using the florescent dye is that absolutely pin point accuracy can be had in how the leak exists.

The fact that you are seeing an indication without a "blacklight" means that you have a great stain. Now you need to have it viewed with a black light. If the leak is coming from the speed sensor, the manifold or the line fittings then I would just reseal. If it is leaking from a body seal or the shaft seal I would replace the compressor with a rebuilt unit from MB. If its a shaft seal and your tech feels confident then its a decent possibility of a cheaper fix. It is a labor intensive job and the seal is pretty pricey from MB and there is a significant chance it won't work but due to your low mileage, its a reasonable repair.

Commercial refrigeration guys use an oil/soap solution that
comes in a conainer with a ball swab that is simply a leak detector that is coated on fittings after a
repair to double check for leaks at fittings that have been reassembled and it is green in color.
Possibly it was used . If so, nothing to worry about.

. . another solution, maybe. .
 

I came across the 'stuff' and it sounds to good to be true. Here's the link: http://www.cryochem.com/CRYOseal.html

If there is a leak and you can eliminate the compressor shaft seal as the source of the leak, the repair can be made without risky guesswork. I don't know what it costs.

Interesting alternative, isn't it? This might have saved you $3K!