Torque converter and car slipping 2004 CLK320
 

Good afternoon, I have decided to join a couple of online forums with the hope that somehow I can find a solution to my problem. About a month and a half ago I started to notice my 2004 CLK320 slipping and making gravel like sounds, with the slipping specially noticeable when going slow at 20 mph and shifting.
I also did some internet research about coolant contamination that mirrored the problem I had. I took it to MB Santa Monica and had the chief mechanic drive it and he also suggested it might be coolant related. Finally I also had a mechanic who used to work at Mercedez for 20 years and specializes in transmissions look at the car and also thought it was coolant related.
It was decided that the radiator should be replaced and the torque converter rebuild, so last week I left the car at the local shop that I have been using since I bought the car two years ago.
This morning I went to pick up my car, they were just getting ready to test drive it, and when they came back I got the bad news that it was still slipping.
I am truly at my wits end, not to try to get any pity, I am really not trying for that, but I bought that car as my bucket list type of thing trying to cheer me up. I am currently undergoing radiation, chemo, and more for which I need the car, and my out of pocket medical expenses are big even with coverage.
Is there anyone here who has experienced this problems with the car and can offer any help or guidance? It would be very much appreciated and I would be so grateful. Thanks.

Not sure about the torque converter re-build??? Did they flush the transmission??? Sometimes it takes several fluid changes before it starts behaving normally again. FWIW, a faulty ECU can cause exactly the same problem as coolant contamination but it's easy to diagnose. Have them clear the transmission adaptation data using SDS. If the problem goes away immediately after this the ECU is the culprit....

The "thought it was coolant related" is very easily diagnosed by inspecting the coolant and ATF.

slippage due to ATF contamination usually means that the clutch friction plates require replacement as the water/glycol in coolant will delaminate the clutches.

The torque converter itself is almost always replaced in a transmission rebuild - the company called CVC have the best ones with updates etc.

ILUVMILS, they flushed it twice from what I was told. I wondered myself about the ECU, when they tried doing the computer test at the shop here ( not the dealer ), they could not get to the transmission computer, and they kept getting speed sensor readings. I myself don't know what that

Update on the car
 

Hi, after several weeks of stress and several sleepless nights, this is what has transpired.
I visited another local shop specializing in Mercedes Benz, spoke to them, explained what had happened so far, and agreed to leave the car there this past Monday morning at 8am. They said they would run the computer on the car.
Now keep in mind, from what I heard from the previous shop ( the one servicing my car for two years ), they had also looked at the car with a computer looking for faults.
Apparently there are different levels of computer for Mercedes Benz. The new shop guy called me at 11am to tell me that they thought they had pinpointed the problem and they needed to do a transmission adaptation.
Two hours later they called again to tell me that the car is fixed, no more slipping, but just in case they were going out for a test drive. I show up at 2pm, pay my bill for basically two hours of labor, and it's been driving without any problems since.
So, what nags me and what I would like your opinions on this: Did I need to spend so much money rebuilding the torque converter and replacing the radiator? Or simply doing a transmission adaptation would have taken care of the problem?
Thank you in advance for any thoughts about this.

Did I need to spend so much money rebuilding the torque converter and replacing the radiator? Or simply doing a transmission adaptation would have taken care of the problem?
Thank you in advance for any thoughts about this.

I would say no, the radiator and torque converter replacement was probably for naught. :(

Sometimes that's the way the cookie crumbles, if it were me I would speak to the shop who did the work and see if they will refund a portion, couldn't hurt anyways. One would think an experienced repair place would have a way to test for water in the ATF. Personally I would not have had them replace the radiator and converter without being sure there was contamination. But hindesight is 20/20. At least your car is sorted now, still less than a trans rebuild right?

It is real easy to drain a little transmission fluid and inspect the color. With that said, it may be that they fixed it when they did the work but did not have a way to reset adaptation (again, real easy to do if you have the correct tool).

It's impossible to say if there was indeed coolant contamination at this point. FWIW, faulty radiators were/are a very common problem on the '04 203/209.....