Hello,

I am in a situation which is an absolute disaster.

Some day ago i think something started to give up but I am not sure what.

Before going to check the codes, since it will take a while before I can do that, I was wondering if the people here might know what problem my car has.

I own a w221 s500 4matic from 2006, i have a 7g tronic as the transmission.

As i was driving i started noticing the rpm start to stutter, as in while cruising at 60kmh the rpm would constantly fluctuate in a rythm from 1250-1500.

Later while continuing driving i noticed it got worse and worse, it started to stutter between gears and took about a second or so to shift through the gears. I brushed it off as a electrical problem or something like that.

And finally when I was a few hundred meters from home I noticed it got worse, the gears seemed to shift strangely like it was trying to decide which gear it really should be in.

As I opened the engine bay I noticed a whine that could be heard only when accelerating in neutral and park, it didn’t seem to come from the engine but under the car, where i noticed it sounded like transmission whine, but abnormally loud.

It might just be me but the gears sounded crunchy while shifting from park to neutral or neutral to reverse or drive. It also sounds like something is scraping while driving.

Later on i noticed a leak while testing the car again the next day, but couldn’t find the leak.

It still drives and no warnings messages have popped up, and the check engine light is off.

Would appreciate some opinions of what it could be.

 

Hello,

I recently had my transmission rebuilt on my 2007 Mercedes s550 base model with 171,000 miles. If you hook up obd scanner to the car and check the transmission module you should get codes if indeed there is a transmission issue. I had a few codes when my transmission was failing. If you have trusted mechanic or transmission place near you then I would bring the car to them. I had my transmission rebuilt with a new converter and gears for $2,700. These cars are notorious for the transmission failing. The fact the car is heavy and also the other issue is Mercedes use to tell people that the transmission fluid didn’t need to be changed cause it would last the lifetime of the car. Mercedes has changed telling people that and it’s recommended to change the transmission fluid every 60k according to my mechanic and transmission shop. Also you didn’t list the miles on your car. From what I have read on the forums is right around 150k miles the transmission starts to fail. Not on every car but a fair amount.

 

My car has 87k miles on it and yeah it sounds like something is slipping in the transmission as it whines a lot. I have noticed that the oil was low in the engine and probably too in the transmission, even though i was informed that it was changed by the previous owner of the car, which was obviously a lie.
Thanks to that i have a leak somewhere, the exhaust smells of oil and the trans is probably dry.
But thankfully the engine runs without error and should probably be recoverable by just fixing whatever is slipping in the trans.

 

MB revised that figure to change the trans fluid to every 39,000 miles.

 

common misconception - if you hook up a OBD2 scanner it will find virtually nothing aside from a few bits of almost pointless data exclusively related to emmison control

ODB2 came in in 1999 in the USA where they mandated 6 out of a possible 16 bits of data on the engine management system must be accessible via a standard diagnostic port situated near the drivers knee - and slowly got adopted elsewhere - the only element it really brought was a standard diagnostic socket - over many years what capability on a car that can be got via the same port has grown enormously

on BM and Merc you can talk to nearly any electronics system on the car over the ODB port - but it has NOTHING to so with the ODB standard. Its proprietary diagnostic capability and programming access via the same port. You need the individual manufacturer diagnostic software to get at everything - the gearbox is on far higher level systems - u can get free ODB but don't bother its pathetic - u need real stuff to pull anything useful on the faults you may have

roughly
ODB2 - free or $10 don't bother
Manu individual model diagnostics from a few systems $45
Manu full system diagnostic and error clearing kit $200
Manu Two way comms and diagnostic $800 to $3000
Full on programming even more


.

 

Ofcourse, I am diagnosing mine with a Star Diagnosis Das Xentry tool.