Hey guys,
It’s my first time posting here! I’ve posted on reddit but I really didn’t find get anything. I’ve also been to multiple mechanics and paid a lot of money for my issue but it’s not yet resolved.
I have a Mercedes-Benz C350 Coupe 2012 W204. Long story short I’ve changed both my cv axles because they were bad. The mechanics told me that they were refurbished OEM ones because new OEM ones cost about $1,500. So there’s that.
I’ve been having shaking when accelerating from a stop. When I press the gas, the car starts shaking, where the “peak” of the shaking is at around 2K RPM. After that, the shaking goes away or is very subtle. Even when I’m at 2K RPM but cruising on the highway or street or anything there’s no shake. It’s just when I accelerate from a stop and it’s driving me crazy. Also, a bit of other context, when I press the gas pedal when cruising, sometimes the car kicks or jerks. I don’t know why. Also, there is a bit of hesitation as sometimes when I press the gas it’s not responsive at all and sometimes it is.
Also, I cleaned the throttle body and when I did I found engine oil in it. Not a huge amount but it’s noticeable. A bit in the manifold too. The car is at 167,000 KM and has had routine maintenance and I usually change the oil every 5,000 KM with Mobil 1 Fully Synthetic oil. The car has been with me for a year but I don’t know what to do anymore. There’s no check engine light but there’s one code P254000. It’s a permanent code. I tried clearing it but it came back. Before this, ai had a low fuel pressure code so I changed the fuel pump but not an OEM one. Usually I buy everything OEM, and all the other parts on the car is OEM, but for the fuel pump I bought HELLA. I’ve heard good things so I assumed it was ok.
Also, the shaking was more pronounced when the mechanic changed the right cv axle. I made him look at it and he made sure that it was ok. I got a second opinion, and another mechanic checked the said cv axle (right) and said it was ok but the other side(that U changed a few months back) had. a small problem. So he changed it but the shaking didn’t go away. So yeah I got cheated out of my money buy the second mechanic, but I believe that if the right cv was damaged or needs replacing, then he would’ve probably made me change it too.
Can anyone please help?
If you have anymore questions please feel free to ask!
Thank you!

 

What scanner do you have?
Do you have a CEL?
How does the car drive?

Check out this thread:

https://www.benzworld.org/threads/p2...sible.3058083/

With regards to your acceleration problem, have you checked the rest of the suspension components? Strut mount, control arm bushings, sway bar links, etc.?

 

Thanks for your reply! I’m using an iCarSoft and no CEL. Also the suspension is good. Recently changed the control arms and sway bar links. Struts as shocks are good too.

 

When was the transmission last serviced?

 

As far as I know, at 120,000 KM which is about 50,000 KM ago. It was under another owner and that’s what he told me. He bought the car at 120K and did the trans service. As for the thread you posted, I had the low fuel pressure code but when I replaced the fuel pump it went away and then got replaced with the current one. Also, the car is kicking/jerking when I press down on the accelerator when cruising.

 

Are you talking front or rear cv axles? What was wrong with the old ones?

If you jack up the car and spin one wheel does the opposite side rotate smoothly, hear anything binding?

Have you inspect the drive shaft?

 

Front CV’s. Both boots ripped. Took them to a mechanic to repair the boots, but they were too late to save. I had OEM refurbished axles put in place. I went to another mechanic that specializes in Mercedes Benz and has some good reviews (shop has been open for 40 years) and he said it’s probably the cv’s. He took them out, apparently tested them, and found out that there’s a small problem with the left one, which he then replaced. I paid approximately $600 CAD for removing, testing, replacing, and putting them back on. The problem is that even after he replaced the left one, the shaking is still there. He said the right one is ok. He never brought up the driveshaft though!

 

Has the front differential fluid been replaced lately? Im not sure what replacing the front cv axles entails, hopefully they checked the diff fluid.

if your not sure where the vibration is coming from I would check the flex discs. id even check the engine mounts and trans mounts. Im just guessing at this point.

Like i said i would jack up the front end and spin one of the tires, see if the opposite wheel rotates smoothly, check for any binding in the axles.