Transmission fluid cooler leak in C230

"I wouldn't buy another Mercedes if it were the last make on earth." Mmmm ... That'll make the factory anxious to help.

It's not an unheard-of problem. As you said, your warranty is long since expired. Nevertheless, there is a reasonable possibility that the factory might be persuaded to offer some assistance. I doubt they'll foot the whole bill. How's your relationship with your dealer? If you haven't burned that bridge, that's the place to start. MB dealers have wide latitude with goodwill assistance decisions.

Even if you complain to the factory, the decision will be bumped back to the dealer level. If you've been a jerk, or told the dealer and/or the factory that you're done with MB, or done all your service work elsewhere, or not at all, or had it done by "your mechanic", don't expect much help. If none of the above applies, you might be surprised. And no, there's no point in trying to blame somebody for not catching the leak sooner. First of all that's not a realistic expectation. Secondly, it cannot improve your chances of receiving goodwill assistance. The key here is that it's GOODWILL assistance. If you're going to be mad anyway, no point in the factory spending a dime.

The radiator must be replaced. The auto trans cooling lines must be flushed. There is a special chemical flush that will clean out the ATF from the cooling system. "Only" the transmission, torque converter, and radiator will need replacing.

I had a similar problem with a 1998 C230 with less than 30k on the odometer. The repair was done under warranty, and there were no subsequent problems. I traded the car two months ago with 94000 miles and got mostly good service for the bulk of my ownership. Sorry for your misfortune.

Sherm

2005 C240 awd

Gary,

If the warranty is expired then I would suggest that you take this car to a reputable MB mechanic that is not associated with a dealership. While the work they stated might indeed be valid, you may be paying a substantial premium for using the dealership.

Josh

Wow! I have a friend that took her 2003 C320 in to the dealer yesterday because it was bucking at above 40 mph and making a clunking noise when shifting from 1st. Service told her today (6/1) the same problem - cooler fluid is leaking into the transmission! They're going to try fixing the radiator - but advised her that it might need a new transmission if this fix doesn't work. Her car has 52K miles - just 2K out of warranty. Also told her that is would cost about $1K for this work but did not tell her how much a new transmission would be. I'll have to let her know to look into this more since other cars have had the same problem. Let me know how you make out - I'm sure she'll be talking to her dealership tomorrow about this.

Alright... If it were me, I'd experiment. Tranny doesn't self destruct the moment Radiator fluid enters... it does make a mess of everything.

This is what I would do. I would have the radiator replaces... flush out the entire coolant system to get rid of any ATF in the cooling system.

Then I would flush out the tranny with new ATF fluid... using the automatic tranny flush machine... which takes out the fluid from tranny and refill at the same time... they use the tranny hose at the radiator to do the job. I would do this two time or three until fluid is clean... They do this while engine is running.

Then see how it goes... it should be alright. You need to do this immediately... Maybe MB dealer can do this job if they have the tranny flush equipment. or you can take it to an independent to have them replace the radiator and flush... and if they don't have the tranny machine... have them drain the tranny as much as they can and change the filter... then after you pick it up... take it to quick lube center who has the tranny flush service to do this flush for you.

Thanks, all of you. Lots of good advice in this thread. Based on a bunch of research that I've done over the last few days, it appears that a leak of this sort is certainly a known problem, and a fairly serious one, but fortunately not all that common.

To Rob--I've not burned bridges with the dealer, so asking for goodwill service wouldn't have been out of the question. I'm pretty sure they only know me as an account number up until now. The same dealership has handled 100% of the service on this automobile (a change is in the wind!), so it really galled me that they'd only offer $3K to take this

4-year-old Mercedes off my hands if I didn't want to pay the $5K for transmission repairs...

But there's a reason we get second opinions on major repairs (Maryo...see that your friend gets one!). I went out and got two more today. Everyone agreed that the transmission shifts poorly, particularly from 1st to 2nd...but from that point, the opinions diverged. To recap:

Ray Catena Mercedes, Springfield, NJ: The seal has gone bad between transmission fluid cooling line and radiator, resulting in cross-contamination of fluids. Transmission, torque converter, and radiator all must be replaced. Work should be done sooner, rather than later, as transmission could fail completely within weeks or months. Estimate: $2214 transmission, $1415 torque converter, $340 radiator, $850 labor, total with tax $5108. Or sell them the car for $3000. (To be fair, I solicited an offer to sell, it wasn't presented side-by-side with the repair estimate.)

Aamco Transmission, Union, NJ: No evidence of seal damage or fluid cross-contamination, no diagnostic codes indicating a problem. If the rough shifting bothers me, they can replace the transmission for $3670 including labor (no need to replace the radiator or torque converter), but there is no sound mechanical reason to have any transmission work done on the car at this time.

Lee Myles Transmission, Union, NJ: No evidence of seal damage or fluid cross-contamination, no diagnostic codes indicating a problem. The manager took me aside to show me what he considered to be very clean coolant, and very clean transmission fluid. He recommended that I not have any transmission work done on the car at this time.

So it looks like I got lucky. I'll be monitoring the fluids regularly and paying attention to whether the shifting gets rougher. I needn't be tempted to drop a lot of money to put a new transmission into this lemon, I can shop for a new car (and a new place to have this one serviced!) at my leisure, and I've found two transmission shops I can trust.

I think I'm going to look up the Mercedes service managers's number and burn a few bridges now...

You done well Gary. Now you know that even the stealer will do something to cheat you big time if you don't investigate or get 2 more opinions.

However, I would highly recommend you change the tranny fluid and filter... It would considerably improve the shifting and smoothness. I have done alot of tranny works to know this.

Tranny is best services... fluid and filter every 36,000 miles... best of all is complete tranny flush... which can be done in two ways... have a shop that has the tranny fluid machine do it in one shot... or if you want to do it yourself... drain and fill tranny 2 times and drive for a bit... and then the third time... drain, change filter and gasket, and refill.

Gary,

What I don't understand is that your car has some undiagnosed transmission problem ("...really banging hard when shifting from 1st to second.") but you're going to drive it around for a while. In the very least you might want to consider having the tranny serviced - fluid, screens, etc. This is pretty cheap when compared to a rebuild. This may also give you a better baseline when trying to determine if there is contamination. Since two tranny shops said that there was no cross contamination and two shops (dealer and one other) said that there was, something is not right. Did anyone mention the flex disks or a little sensor known something like the automatic transmission overload sensor? The flex disks can wear out and cause thunking. And the job of the sensor is to soften the blow between shifts under load by retarding the spark for about 1/2 a second (and avoid tearing up the tranny).

Josh

God, what a moron. Guess it's true, you can lead a horse to water ... I'm sure those "two transmission shops I can trust" will be there for you. Still ignorant, but no doubt they'll be fully prepared to offer goodwill assistance for your out-of-warranty vehicle. Makes you wonder how transmission shops got such a poor reputation as a breed. Probably misjudged, each and every one of them. Ah, well. You go ahead and piss off the dealer. Asshole probably doesn't know anywhere near as much about a Mercedes as the Aamco bunch. And that Lee Myles, why he probably designed the transmission himself for Mercedes, so who better to believe? Anyway, it feels so great to be self-righteous about something you don't really understand, so who cares if the damn car gets fixed, right?

Gary, Here's an update on my friends Benz. After finding a few places on the web noting this same problem we called Service at the dealer. He tells her that it needs a new catalytic converter in addition to a new radiator and other parts. She asks "how much more will that be" and he says "we're only charging you for the radiator". So we mention that a few other people on the web posted this problem and she's been happy with the dealership, has all her service done there, etc. and there should be some "goodwill" in this case. He then states that that is why they are only charging her to replace the radiator. Benz is picking up 1/3 of the cost, the dealership is picking up 1/3 and she is paying for only the radiator which is the other 1/3. They had already decided that before we called! So, I'm thinking that this is probably a known serious problem - otherwise why would they have offered so readily to pick up 2/3 of the cost? So today is Monday and she hasn't heard anything about getting the car back yet - but they have also provided her with a loaner. It appears that this dealership is being fair - I've been happy with them for the 4 years I've been taking my SLK there and I recommended them when she was ready to buy her car. I'll post again when she gets the car back with what was actually done and how it's running.

Fair? I'll say they're being fair. More than fair. As far as your suspicion that they are trying to cover up a known serious problem, isn't it also possible that the dealer recognizes that the failure is unusual, and that both the dealer and MB want to spend some money to retain a customer? Don't be so suspicious and quick to condemn. The dealer's in business to make money. So is MB. They do that by selling products and services to customers. They don't sell products and services to unhappy customers. You don't need to look for some sneaky motivation - it's just common sense to try to retain your customers.

I don't see the need for name calling. You obviously trust the diagnosis of one dealer as some kind of God beyone reproach vs two transmission shops. It's not clear to me who is right here.

As for dealers, here's a case I experienced personally here in NJ. My girlfriend bought a Pontiac that a friend of mine had, which was a well maintained corporate fleet car, with 85K miles. About 6 months later, the ABS light would come on intermittently and the brake peddle would pulse. She took it to the nearest Pontiac dealer for that and also complained that the power steering sometimes made a squeal.

When she came back, she told me they wanted $1200 to fix it. It had a bad ABS computer and a power steering leak. Of the $1200, about $750 was for the computer. I was unaware of the power steering issue. I asked her if she had any indication of fluid on the garage floor, and she said no. I did a visual inspection and drove the car and the steering worked perfectly, there was no sign of any leak. The only slight noise I could get it to make was if you turned the wheel hard all the way to the stop, which isn't unusual.

She took the car to another Pontiac dealer and the ABS was fixed with a new wheel sensor for a cost of $225. Now, this is an interesting case, because it's impossible for this to be some kind of misdiagnosis. That car has two computers, one for the engine, one for the ABS. Those computers have extensive diagnosic codes. They can tell you if a wheel sensor is shorted, if a wire is open or grounded, etc. And they also perform a self test to verify the computer itself is OK. It's just about impossible for me to believe that the computer was showing the first stealership a code that says bad computer when in fact, it was just a bad wheel sensor. And the power steering worked fine for years later without any leak or problems.

So, I think the OP has every right to be suspicious of a dealer after getting two independent opinions that contradict the dealer. If it were me, I would probably take it to another dealer and seeing what they have to say too.

She isn't being suspicious, quick to condemn, or accusing the company of having a sneaky motivation. It's well known that at times, some car maufacturer's know that they are having premature failure of some component. And as a result, if someone comes in with a car with that problem, but it's out of warranty, they will offer some type of assistance.

I had the very same experience with Pontiac. The steering rack in my

6000 was becoming difficult to turn, but was out of warranty. It was a known problem, the dealer told me so and I wound up paying half to have it replaced, with Pontiac picking up the rest. IMO, it's a lot more likely that you're going to get relief like that, for a known problem, rather than just a random failure that happens to occur.

Cat converter is covered under federal law of 8 years or 80,000 miles... any emission system failed withing those period gets full coverage... even if it is your oxygen sensors.

This dealer of yours is honest... so stick with them.

Rob, I'm sorry you misunderstood my posting. I would not use words "suspicion", "cover-up" or "sneaky" with this dealer at all. Just found it odd that the first thing they said was that it was "out of warranty" and then, a day later, without even asking, the offer is made to pick up part of the costs. This dealership is one of the best as far as I'm concerned - otherwise I wouldn't have referred my friend to them in the first place. She lives more than 50 miles away and went there on my recommendation. Here's the update as of today: they have now determined that the transmission needs to be replaced and she will not get her car back until next Tuesday at the earliest. Costs are approaching $9K for this repair and she will not have to pay anything! They told her it is a manufacturing defect and will be fully paid for. So, stick with this dealership - you bet I (we) will ! ! !

In four years the radiator leaked through? That's really not good.

I'd try a call to the district service manager.

Update 6/16: Well, she got her car back. They replaced the radiator and torque converter twice and it failed both times - so they decided the transmission needed to be replaced (and another torque converter). Entire repair cost was picked up by Benz (Goodwill was noted on the invoice). Her car was only 2000 miles out of warranty. So, after almost 2 weeks the car is fixed.