My wife and I are in our early 60's decided to buy our first MB. Eased into it with a used 2013 C250 27k miles. First week was great and then the temp gauge spiked to 120 degrees while driving on the freeway, lost power and immediately pulled over. Sat there for 5 minutes, no smoke, didn't smell hot, gauge went back to normal, so I drove it immediately back to CarMax where I bought it.


They checked it out, coolant was good, told me to take it to a MB Dealership since it is still under factory warranty. It's now been there for 6 long weeks. They have changed the module, replaced some pins, reset all of the codes, completely flushed the engine with some type of special solution that we had to wait a week to get and I got the call Friday that it is still periodically spiking the temp gauge at high speeds and simultaneously loosing power temporarily, and then it returns to normal.


About 30 years ago, I had a Volvo with a 4 cylinder turbo and it did the same thing right before the turbo went out. I told the service assistant and service manager about this a couple of times and they get this grin on their face and pat me on my head and direct me to the coffee bar. I will say that on Friday, during the call telling me that the great "flushing" exercise was a failure, the assistant did tell me he would mention it to "someone". Then he asked how the loaner was working for me.


Don't get me wrong, the guys at MB have been very nice, they did hook me up with a loaner, but this process of trying one thing a week is starting to get to me.


I could take it back to CarMax and they would buy it back, but I feel like this car has become like some sick dog I found on the side of the road and I am now determined to nurse him back to health and keep him as a good and trusted companion!


I've checked some of the threads on MBWorld and found that most of you people, unlike me, are really smart when it comes to anything MB. Anyone have any ideas for me? It's for darn sure that the German engineers at MB are not able to figure this out. And why do they just try one thing a week, why not just hone in on this and find out what the heck is going on?


Thanks for the help!


P.S. A day or so before this happened, the "check coolant" light came on. Took it in to CarMax, they said it was fine and "reset" the code, whatever that means. It showed the coolant warning again after it spiked and again, the coolant level was fine.


When it spikes, it does it randomly, not a constant thing. It does seem to loose power slightly when it spikes as well. If I keep driving when it does it, it stays like this for a few seconds and then back to normal.


Thanks for any help anyone can give. Are there any psychologists out there that can explain why I don't give this car back to CarMax and get another??

 

Sorry for the long Post, it was my first, I'll get better at it.

 

moved to W204 forum...

 

In my experience most service visits take 6-8 weeks. Much of that time is waiting for engineers back in Germany. I've had my car since October and have only had possession of it for about half of the time I've owned it.

Also, It seems like they like to randomly replace stuff until something takes.

Flushing the coolant system as a fix seems like a waste of time to me. I would expect something more like fans, thermostat, pump or related software to be causing this.

The power cut could just be the ECU reacting to the temperature.

 

If you get a CEL then scan it. With the sounds of these symptoms, I would also say it would be related to the cooling system.

My first thing to look at is the Thermostat. Some what good CEL readers can read the stored memory and see what has happened previously in the car. Also COMMAND itself records a few things here and there from power, to voltage, to issues in the secret menu of course.

That might be a good thing to look into.

 

A faulty thermostat was my first thought but that is simple enough the dealer should have been able to get that in less than a day. My second thought would be a fan issue but that isn't as likely since the problem happened at speed.

If I were the OP I would find a local indy shop and ask them for opinions.

It took a dealer over 6 weeks to fix my navigation system and they busted up a bit of the car's interior in the process. End fix was just to put in a new unit (which I said on day 1).

 

Sorry to hear about your troubles. I say take it back and start again if you have that option. You're 60+ and I imagine there's better things to do with your time. Make no mistake, they're chasing the rabbit on YOUR time.

There are millions of MBs out there living 200k+ trouble-free miles, and you could be one of them. Nothing special about a 2013 C250. I say move on and try again.

Good luck.

 

I agree .

TX. Take the sick puppy back to the pound & try another one if you are game.

I really do wonder about the standard of motor engineering in the USA , in six weeks it should be well & truly diagnosed .I suggest that they have not tried hard enough or not spent $ enough on diagnosis ie changing modules or are just plain incompetent.

Hondas are nice cars.

 

I think it could be a combination of things as to why it takes so long. The dealers around here are incredibly busy. Also, I think they get paid by the factory for use of the loaner vehicles. I'm not sure they drag their feet on purpose but I don't think there is much incentive to get the job done quickly and correctly.

 

I think it's a slow shift of the technical minds to the tech industry. It's tempting when they start you with ridiculous salaries (by ROW or even Rest-Of-Country standards), 4-day work weeks and the option to work from your living room. Sure beats doing oil changes for 10 years as you apprentice to become a master tech.

A sort of "brain drain", if you will, not unlike the children of 3rd generation farmers going into the city to make their mark instead of toiling in the dirt.

 

Doesn't seem likely that it is actually spiking the temperature, just that the computer thinks it is. Sounds like a sending unit/sensor or connection problem to me. Hard to imagine that's not where they looked first.

 

Well, for my car they once had the engineers back in Germany write a new firmware version. These cars seem to require NASA level TLC, lol.

 

New firmware version just for you? For a handful of Maybach owners complaining about something, maybe. For a single owner of an entry-level C-class, I'd have to see documentation to believe that.

 

I find it hard to believe too. But that's what the service department told me.

 

Service Advisors. I'd add a real helping of salt before I believed anything they told me.

Consider that Service Advisors are at the bottom of the food chain and too removed from those writing machine code. And privvy or not, remember these guys are part salesman, part customer service rep, and would likely tell you anything for a sale or to get you to feel better about your visit.

 

Like "I'll call you tomorrow", lol.

My issue was with the Comand firmware. When I came in they said it was just a setting. It took me a day or two to convince them otherwise. Then they tried a reset. Which failed. Then they tore the interior of the car out, took the dash out, trunk trim, instrument cluster, etc. to perform testing. That all failed to fix the problem. They went to look for a firmware. None existed so then the issue went to the software engineers in Germany. At which point they developed a firmware that could be reloaded into my Comand HU. The new firmware also failed at which point they then ordered a new HU.

I was in disbelief about how complex it all had become.

 

6 weeks wow.

You are one patient man. I realize you have a loaner, but ...

You would think (hope) that this is a computer or sensor issue. It couldn't be something simple like that thermostat, fans, etc, as I'm sure the dealer would have checked those items first.

Good luck.

 

Well, that's what I used to think, lol. That's why I pointed out the entire interior of my car getting disassembled from dash to trunk for a navigation system bug.

 

I could'nt begin to diagnose the problem. I had a couple issues with my 2012 CPO, but each time the check engine light diagnose guided the techs to fix the issues - thermostat and fuel level sensor. Personally,. I'd return it, if you have that option, and get a Camry-unless you must have the driving experience which only a luxury German car can provide; which many of us on this forum do.