[eatmydave]

I bought a 92 500SEL back in October. I went to use the AC for the first time this week and it was blowing really hot air. As if it were set to HI on heat. I pushed the blue button on the center vents and it made no difference. I brought it to the dealership (RBM in Atlanta). They did a charge and leak test and told me the evaporator has a leak and would be over $3000 to replace. That's 60% of what I paid for the vehicle!!! My jaw dropped!!! I told them not to do it and didn't get an estimate for the work. However, the AC has been working since then. I know it will stop when it loses its charge, but it bought me a few weeks I assume.
When I left the dealership, I noticed a new problem: The air blows ice cold from the center vents, but the two vents on the sides of the dash and the defrost vents (top of dash) still blow really hot air. I am not about to bring it back to the dealer for this problem.

Here are my questions:

1. Is the problem with the air only blowing out of the middle vents and not the side vents related to the douvalve? If not, what else could it be?

2. I found a new evaporator complete with expansion valve for $200 on ebay. I have a friend that can do the labor. Is it really not recommended to use an after market evaporator? I just can't fathom spending $3000 on this. Here is my logic, call me crazy if you want... but if it costs me $500 to replace the evaporator, even if I only get one summer out of it, it would take me 6 years to get to $3000! I don't plan on keeping the car that long (maybe 3-4 years) before I have enough saved for an S55.

I have searched threads here and maybe am not looking hard enough, but I have not found the answer to these questions. Any help is greatly appreciated!

 

[DaveMck]

I think it takes something like 20 hours (maybe more) to change the evaporator. When you add in recovery and refill with freon, plus misc. small parts, I think your $500 is conservative. A busted evaporator is a common terminal disease for w140, from an economical point of view.
Good luck,

 

[bayhas]

Here are my questions:

1. Is the problem with the air only blowing out of the middle vents and not the side vents related to the douvalve? If not, what else could it be?

2. I found a new evaporator complete with expansion valve for $200 on ebay. I have a friend that can do the labor. Is it really not recommended to use an after market evaporator? I just can't fathom spending $3000 on this. Here is my logic, call me crazy if you want... but if it costs me $500 to replace the evaporator, even if I only get one summer out of it, it would take me 6 years to get to $3000! I don't plan on keeping the car that long (maybe 3-4 years) before I have enough saved for an S55.

I have searched threads here and maybe am not looking hard enough, but I have not found the answer to these questions. Any help is greatly appreciated!

1-Yes this is typical stuck duo valve.

2-Go ahead and use the ebay one, you can go through at least 6 of them in 6years (assuming one aftermarket per year) for the price you pay for one at the dealer, like you said, 3000 is not aweful as a lump sum for a repair, but considiring thats about half the value of the average W140, its kinds stupid to pay that...

in your case, I would look into the duo valve first, then try to patch the leak if its a slow one, 2-3 weeks leak, you may be able to seal it with after market stuff...

 

[eatmydave]

Thanks for both the replies guys!

Seriously 20 hours or more to do the evap???? WOW!!! I guess $500 is extremely conservative and may not be realistic. WOW! What do they have to do? take the motor out piece by piece??? Just kidding.

I will look in to the duovalve first. I was also going to ask if a sealer would be advised just as stop gap for now. Thanks for letting me know.

 

[DaveMck]

Thanks for both the replies guys!

Seriously 20 hours or more to do the evap???? WOW!!! I guess $500 is extremely conservative and may not be realistic. WOW! What do they have to do? take the motor out piece by piece??? Just kidding.

I will look in to the duovalve first. I was also going to ask if a sealer would be advised just as stop gap for now. Thanks for letting me know.

Evaporator R & R requires R & R of entire dash and center console. There is a picture of a car in the torn down state and it's a whole lot of dangling wires. It might be easier to remove the engine (not that it would help your problem). Someone might claim faster repair times but I doubt it.
Hope it's the duovalve or such a slow leak that some R134 with leak sealer will help.

 

[eatmydave]

Thanks Dave!

I hope the valve and sealer will do the trick too.

 

[DHoecher]

Does anyone know if the evaps being used as replacements currently in 140's are the E class ones mentioned in an old thread or a redesigned s class 140 evap thats smaller for older model replacements as there is a filler piece being used now for retrofit?

 

[4benzes]

Im not sure if the product is out there, but I think it was called CRYOseal or something similar that I used on my W140 when I had a leak a few years ago. I was heated because after seeing a W140 broken down like that to do the install, I would never want to drive that car again. It looks like a train wreck, and I wouldnt trust just anyone to do that install.

 

[echandler]

I was not aware that R134 leak sealants were available, so I did a bit of searching and found this:

Aircondition.Com - Automotive A/C Knowledge Base - Leak Sealers

And yes, one of the products is called Cryo Seal

Before you embark upon an evaporator replacement, you could consider one of the sealers. Apparently the technology has come along way.


Just a thought.

 

[echandler]

Im not sure if the product is out there, but I think it was called CRYOseal or something similar that I used on my W140 when I had a leak a few years ago. I was heated because after seeing a W140 broken down like that to do the install, I would never want to drive that car again. It looks like a train wreck, and I wouldnt trust just anyone to do that install.

Is the sealant still working for you?

I agree with your post - I would not want to subject my car to the dismantelling required for an evap replacement - especially if the sealant works well.

Please advise - thanks

 

[bayhas]

that realy depends on the size and shape of the leak, however, its not a bad idea to try the sealant first...