MBNUT1

Trying to diagnose some less than seamless upshifts on my 2010 E3504matic. Dealer ran diagnostics and found nothing. Updated the software which didn't cure the problem. They are suggesting that they test the ATF for presence of coolant. Don't think that it will be expensive ~$75 but I suspect with this chassis it is a real long shot because when I search the W212 threads I don't see any reports of radiator issues and additionally unlike the W211's no reports of coolant contamination of the transmission fluid. So I am thinking that this would be a wasted exercise. Anybody have any experience to suggest otherwise?

LALALAND

You can try Blackstone oil analysis. It's $28 and they give you all type of info. I heard you can also chat with them after you get the results.
https://www.blackstone-labs.com/prod...ree-test-kits/

kajtek1

x2 on Blackstone. Have been using them for 20 years. Don't always like their comments as their opinion change depends on situation, but numbers don't lie if you learn how to interpret them.
If you have 7G, getting a sample can be tricky, but opening the plug with engine off will start draining ATF and all you need is 100ml, so I would not worry about dropping level.

MBNUT1

Thanks for the reply.

I've used their labs before when I was trying to figure out whether the dealers accelerated service intervals were legit. The lab results at 7500 miles oil supported the factory recommendations of 10k oil changes. ie at 7500 miles the oil was still good.
If I do this I will probably let the dealer do it as they only were going to charge $72.50 to pull the fluid and test it. The point of my post is that I think that I have come across zero evidence of W212 radiators issues and there is little likelihood of contamination so it will probably be a waste of money.

kajtek1

I never consider troubleshooting a waste of money.
If you read older forum topicks, before scanning become advanced to narrow the problems, lot of owners dumped even thousands of dollars on parts replacement before they luckied in replacing right part.
$72 comparing to cost of new transmission sure is a bargain.
But dealer's oil testing sounds fishy. What they do?

MBNUT1

Thanks for the reply. I agree with the sentiment. Just trying to not get my hopes up that it's only a radiator. If it were a W211 then there might be a pretty fair shot that it could be. I'm not sure what they do. They claim to have a new tool that can detect minor amounts of coolant in the transmission fluid. I suspect the process is put the car on the lift, open the drain plug and collect a small sample and test it. Most of the time is probably involved in getting the car in the air. Thinking $72 = 1/2 hour labor.

kajtek1

If they test only coolant in ATF, for less money you can send the sample to blackstone and have full test of oil quality and contaminants.
With some recommendations to top it.

MBNUT1

Good point on the contaminants, I had the transfer case rebuilt a couple of months ago due to a bearing failure. They did replace the transmission fluid at that time. The transmission shifted perfectly afterword but I suspect that TCU solenoids may have gotten contaminated and are causing the less than seamless shifts.