Carsy

Good work Ed. Glad to hear it is all sorted out. Persistance wins out over B.S.

Glyn M Ruck

This only occured with Valeo radiators fitted from 2000 to late 2002. Leaks developed between radiator & tranny fluid cooler. Fixed by fitment of a Behr radiator.

grane

Thank you for clearing this up!

tasho3

The whine on my car seemed to be getting a bit louder, but now is getting quieter, and sometimes I don't even notice it. I was driving the other day, maintained the speed at 62mph (thats the only speed the whine is noticeable) and downshifted and up shifted and the whine didn't change one bit. As I was going through the shifts there was not breaks in the whine, or change of tone. I have asked passengers and they all tell me the whine seems to be coming from rear drivers side. My previous tire on rear drivers side was cupped, and I replaced to 18 inch wheels and that's when I noticed the whine. Another memeber was able to get rid of the whine just by rotating his tires, so I'm hoping that the noise is coming from my tires and not the trans as my car is out of warranty already

edV44

Unfortunately, we, the end users have no way of knowing if the transmission fluid have been diluted/contaminated or if the transmission fluid is of the correct level as there is no tranny dipstick on these cars.

tasho3

in plain simple english; WE ARE FU*KED

penguin7890

Know the last post is a couple weeks old, but wanted to mention my situation. It might help some of you, but I sure am getting nowhere with my local dealership. Bought a brand new 2012 GLK 4Matic in March. Test drove it, but in super bad traffic so we didn't get it above 20 mph. No problem, had GLK loaner cars and test drove another, so I knew what I wanted. When I drove it off the lot down a road and got it up to 40, I heard a whining sound when letting go of the gas (but not pushing the break) that I could only describe as a "whooooo" noise. Called the salesman, he said that a 4matic would be louder than my old c-class and I would get used to it.

The noise got worse, and after a 5 hour road trip, you couldn't get my husband out of the car fast enough. This shouldn't happen in a new car. It sounds like you are blowing air in a glass bottle.

Had the shop foreman drive with me, he heard it right away said it was a faulty transfer case, a replacement would solve the problem immediately, but that there was nothing actually wrong with my car, just an annoying noise.

So we brought it back to have the Transfer Case replaced. They said that my noise wasn’t loud enough for Mercedes to pay for it – that you can’t just replace your transfer case, the entire transmission has to be replaced. Then they change their story that Mercedes would pay for it, but that it could be much worse, and then Mercedes wouldn’t do anything for me, if it was much worse.

Then they said that the 4matic is much louder than a 2 wheel, and that loud whining noises are very normal with all 4matics and that I could trade it in for the RWD GLK if I wanted to. Then that maybe I would enjoy a Hyundai instead. !!! I really hate this place and am at my wits end.

Is this normal? Are 4matics loud and whiny? (I don’t believe so). Will a brand new transmission fix it or make it worse? If this happened when the car had 18miles on it, and is MUCH worse a 8k, what will happen later on? Do I just want a RWD?

frogs9497

I don't understand how there would be any circumstance here where Mercedes would not be responsible. Maybe I'm not understanding, but why would you be on the hook if things "became worse?"

LILBENZ230

Try a different dealer?

RLE

It's the other way around. The trans cooler is a separated part of the radiator and as far as I know all cars and trucks with auto trans have had them for decades.

This is well known at MB and back in the days of the W203 the model that had this failure most was the C32. Engine coolant would get into the trans and it would start malfunctioning. The dealers use a standard test of the trans fluid to see how contaminated it is and above a certain test number the trans, along with the radiator, must be replaced.

The bad radiators are made by Valeo in Italy, according to my dealer tech.

edV44

4matics being noisier than regular RWD is total BS. If there is a difference, it is imperceptible. In short, all things being equal, an RWD will sound the same as a 4matic. I am sure Merecedes will honor the warranty and replace all the offending components and it will not cost you anything. The dealer might be giving you the run around. If the problem is not resolved at the dealer level, contact MBUSA customer relations directly.

RLE

More info as of today.

I asked my dealer's service manager about this and he said the problem has gone away. I asked for details in re: the trans fluid test for coolant contamination and he said it was a litmus test. I asked if they were doing this test now when doing trans fluid changes and he said not any more. He did say that the C32s seemed to have this happen more often than the rest.

So, this is a non-issue.

Glyn M Ruck

The bad Valeo radiators in W203 were French.

penguin7890

They said that I would be deciding to replace the transmission, with full understanding that it could get worse. If it did get worse, Mercedes would not put the old transmission in, that I would be left with a worse noise. Or would just need to trade in my car for a different one (I am SURE at my expense).

LILBENZ230

You need to take it to a different dealer ASAP.

RLE

OK fine. The story in 2005 was that they were Italian. French is even worse.

But, you win. I give up.

jctevere

Just came across this thread... I no longer have my 2009 C300 4Matic, and now have a 2012 C250 Coupe. I had this "howling noise" since my C300 was new, and had it up until 45,000 miles. Had no issues with my vehicle or transmission. Perhaps it is just the 4matic system being loud/creating resonance. Like the rest of you, I would ALWAYs hear this on the highway at around 60-62mph - especially when I was coasting. I would also hear it when coasting at a slower speed, I want to say around 32-40mph.

Neither of our two 2012 RWD C250 Coupe with the 7G tronic plus transmissions do not experience this howl. However, our remaining 2011 C300 4matic does. So this leaves me to believe that the noise comes from 4matic - or possibly just the nature of the C300 engine, but not the actual transmission itself.

ggms16

Happened to me... Exactly the Same thing the OP described in the first post.

I'm looking for a replacement transmission now since I've got no warranty.

ggms16

Anyone knows if this problem can be relieved or dissembled with an oil change or something?

MisterD31

I noticed the howling shortly after I purchased my 2009 C300 4matic. I purchased it CPO in early 2012. The MB Dealer took it for a test drive and suggested that it was the transfer case and replaced it under warranty. Funny thing is, the 2012 c300 4matic loaner they gave me while they were doing the work made the same sound at highway speed. After the transfer case swap, it did seem to get better, but, I still hear the noise from time to time. Does sound like a very annoying, less than optimal trait of the 4matic system.

ggms16

The bad new is that all w204 4matic cars have a transmission and a transfer case in one piece. They cannot be replaced separately