Ductard

I have a 2008 C300 with ~145K miles on it.

Within the past month or so, the transmission started acting up. Under light acceleration / maintenance throttle, the tachometer bounces back and forth...you don't really feel it "slipping", but you can see the needle oscillating.

Under heavier acceleration, there is a shimmy/shake almost like you are running over tiny rumble strips.

The check engine light came on soon after I realized there was an issue....I assumed low fluid level, but a garage checked that out and also ran a diagnostic and found no engine or transmission error codes indicated.

I had the dealership do all scheduled maintenance until 100K miles or so, so while I haven't verified my records I believe I had the transmission service done. Nonetheless, went ahead and had the garage I took it to change the tranny fluid and filter in the hopes that would fix the issue.

It did not, the garage said the next step recommended by MB is to replace the torque converter. While I was OK with the $350 tranny service, I am not as OK with a ~$1,800 repair when the garage isn't sure that's the issue.

When I pressed the mechanic, he said that given the mileage of the car if it was him he would probably just drive it until failure.

Any other ideas here? The check engine light just came on again today so I'm wondering if the car has finally sensed an issue with the TC...

Plutoe

You can guess all you want, however to eliminate the speculation have the car scanned---find an indy with DAS Xentry and learn the real story!!

Flarearrow

You gotta take it in to a real Merc dealership. That's the only way to know since they will have the breadth of tools and access to knowledge database.

I gave up my 05 C55 AMG when its tranny was doing funny things at 73k miles. Took in to Helms Bros in Bayside, Queens. They said I would need a new tranny. Their diagnostics was able to compare engine speed to driveshaft speed and it was out of tolerance, hence slipping.

Esalazar81

I'm having similar issues. Took it to get the transmission service at an independent benz shop and was told this issue is due to having a failing Valeo radiator allowing coolant to get into my transmission via transmission oil cooler built into the radiator.

They recommend replacing the radiator then doing the transmission flush at that point. They said issue could be fix with one transmission flush service or as many as 4. From what they experienced in dealing with other benz with the same issue.

I check my self and yes I have a Valeo radiator and it's been a know issue with different C classes.

I call another shop and explained what I was told and that They DON'T recommend doing the flush as in their experience it makes the issue worse. So now I don't know who is right and what to do.

I need to fix the slipping on my car. But in my current situation I can't afford any major repairs and this is my only car for transportation.

Any advice would be appreciated.