Hi:
I have used this website to guide me trough many repairs in the last several years.
My mother-in-law has a C300 2009 4matic sport. The car seems to shake between 10 and 20 mph at 1200 to1600 rpms-if the car is driven very very easily: light on the gas and let the car slowly go through the gears.
I changed the:
-Spark Plugs
-Air Cleaners
-Transmission/rear engine mount
-2 Motor Mounts right and left
-Drive shaft
- 2 flex discs
-Cleaned the MAF sensor
-Chevron Techron fuel injector cleaner -2 bottles through last 2 tanks of gas
After all that the car still shakes.
I know the car needs front rotors and pads, will do this weekend. Although, there are no driving signs that the rotors are bad. I did notice the inside of the rotors have deep groves in them as I crawled out from under the car the last week doing all the above work,
I don't think it could be the rotors as their is no vibration while braking and it happens when accelerating gently.
The car does have a rough idle while in drive but not park. The car vibrates and sounds rough in Drive whiles topped, which probably is a hint to what is causing the shaking at the above speeds and rpms.
If you drive the car more aggressively or even normal, not gradually getting up to 20 mph with barely giving it any gas, the shaking either does not happen or is very very hard to detect.
ANY HELP WITH WHAT IT CAN BE WOULD BE AWESOME.....NOT yelling just wanted to highlight the plea for help.
Through all my reading I understand it could be:
Tires
CV joints
tie rods
But I am thinking, maybe it is related to the rough idle while in drive which could be:
Torque converter
Transmission ---fluid or tranny
EGR valve
PCV vent
Coil
Coil Extender thing that connects to the plugs
Anything else?

Any help on what this could be and how to test for it would be very appreciated.
Thanks,
Gary

 

Front & rear differential oil change
Transmission/tc oil change

 

I have continued to research and it appears that the Front Left axle / possibly the right when in Drive or Reverse is most likely the culprit. Many are surprised that the Axle/CV joint could be a vibration...feeling like a rough idle when all the rest of the work I have done to eliminate the issue has been done. Luckily, all the work I did was needed as all mounts were bad, plugs had 115K on them, flex disks and carrier bearing were shot.

I am going to replace the front rotors and pads this week and will inspect the front axles.

This post does an awesome job of explaining and supporting the above suspect of the axles.

I will update with what I find after replacing the brakes and inspecting the axles.
Thanks for your reply.

 

[QUOTE=Good-Guy;8804979]Hi:
I have used this website to guide me trough many repairs in the last several years.
My mother-in-law has a C300 2009 4matic sport. The car seems to shake between 10 and 20 mph at 1200 to1600 rpms-if the car is driven very very easily: light on the gas and let the car slowly go through the gears.
I changed the:
-Spark Plugs
-Air Cleaners
-Transmission/rear engine mount
-2 Motor Mounts right and left
-Drive shaft
- 2 flex discs
-Cleaned the MAF sensor
-Chevron Techron fuel injector cleaner -2 bottles through last 2 tanks of gas
After all that the car still shakes.
I know the car needs front rotors and pads, will do this weekend. Although, there are no driving signs that the rotors are bad. I did notice the inside of the rotors have deep groves in them as I crawled out from under the car the last week doing all the above work,
I don't think it could be the rotors as their is no vibration while braking and it happens when accelerating gently.
The car does have a rough idle while in drive but not park. The car vibrates and sounds rough in Drive whiles topped, which probably is a hint to what is causing the shaking at the above speeds and rpms.
If you drive the car more aggressively or even normal, not gradually getting up to 20 mph with barely giving it any gas, the shaking either does not happen or is very very hard to detect.
ANY HELP WITH WHAT IT CAN BE WOULD BE AWESOME.....NOT yelling just wanted to highlight the plea for help.
Through all my reading I understand it could be:
Tires
CV joints
tie rods
But I am thinking, maybe it is related to the rough idle while in drive which could be:
Torque converter
Transmission ---fluid or tranny
EGR valve
PCV vent
Coil
Coil Extender thing that connects to the plugs
Anything else?

Any help on what this could be and how to test for it would be very appreciated.
CATALYTIC CONVERTER

 

[QUOTE=fosterbrandon18;8880883]The car had a RUSTED subframe and falls under extended warranty Mercedes issued in February 2023, extending the rear subframe warranty from 4/50K to 20years/unlimited mileage for all owners. Mercedes got around making this a recall which would come up with a Vin# search but warranty----no. The letters mentioned in the URL: location below were not received by any of my family members that have three cars affected by this extended warranty, under three different owners at three different household addresses.
https://static.nhtsa.gov/odi/tsbs/20...33780-0001.pdf Paste this string to the left into your URL to see the recall notice. Pasted unformatted excerpt below.
They covered the cost of only the SUBFRAME but not the tire, springs, brake lines that were all eaten buy the rusting subframe raining rust particles down on these components; so, the free warranty work carried a $9,600 recommended repair list with it. I think the extended warranty instead of a recall without the letters apparently being delivered should be criminal as clearly people lives are at risk.
FINAL FIX FOR THE SHAKING for this instance was:
The new subframe corrected the suspension being out of specs., the new rear tires that were eaten by the bad subframe AND I also had a bent rear rim...which was a surprise. When the car came back from MB...ALL FIXED. It vibrated. I had new tires put on it and it still vibrated. I took the tire with rim off the passenger side because that was more badly scalloped before putting on the new tires and with the donut/spare the car rides fine.
So, I am taking the car on Friday to a new tire shop that can ROAD FORCE BALANCE to have the old rim tested for being bent....should be that, if it is I have a new rim (replica) inexpensive but great and will move the tpms/valve and tire over to the new rims, road force balance it and be done...I hope. Probably will put some cat cleaner it it a think about having new tranny fluid in it...not sure if that is good or bad to do, research seems to show yes and no.

IMPORTANT EXTENDED WARRANTY INFORMATION Mercedes-Benz USA, LLC (MBUSA) has extended the warranty for the rear subframe on the vehicles listed below, from the original New Vehicle Limited Warranty of 4 years/50,000 miles to 20 years/unlimited miles, and applies to the vehicle regardless of ownership. This warranty extension applies to the replacement of the rear subframe under the standard warranty terms and conditions in the event the subframe experiences corrosion with perforation (holes). The extended warranty is applicable to the following vehicles: Model Year Model (platform) WIS reference 2005 - 2011 SLK-Class (R171) AR35.10-P-0010V 2012 - 2017 SLK-Class (R172) AR35.10-P-0010V 2012 - 2016 CLS-Class (C218) AR35.10-P-0010EW 2013 - 2016 SL-Class (R231) AR35.10-P-0010RK 2008 - 2015 C-Class Sedan/Coupe (W/C204) AR35.10-P-0010CW 2010 - 2015 GLK-Class (X204) AR35.10-P-0010CW 2010 - 2016 E-Class Sedan/Wagon (W/S212) AR35.10-P-0010EW 2010 - 2017 E-Class Coupe/Cabrio (C/A207) AR35.10-P-0010CW All models require cavity preservation on the rear axle carrier after the replacement according to AR35.10-P-0010-03A. The VIN–specific part number for replacement parts must be determined according to the equipment variant via the parts process in Xentry Portal.

Good luck

 

the 2 o2 oxygen sensor needs to be replaced. If its a cold start issue and fades after engine is heated, then it’s those parts….

 

have you done the lerning procedures of any kind for throttle position and transmission /tq converter etc

 

Sounds like the transmission fluid went out. Low rpm granny driving particularly uphill creates a high torque situation against the transmission fluid which if its worn won't build enough hydraulic pressure so it'll feel like a weird shudder like somethings about to break.

Slippery pete hand pump on Amazon
722 adapter on amazon
Vaico filter/bolt/gasket kit for the transmission pan
If you wanna give Amsoil ATF a try you'll like it,
https://www.amsoil.com/p/amsoil-oe-m...tf/?zo=7236674

Make sure to sign up for the PC program for 25% off

 

I had the same issue. 2008 C300 4 matic. Felt it first as a small vibration through the shifter... and got steadily worse. ended up replaced all the engine mounts and had to replace both axles at the same time.

the 4 matic is a different beast to replace engine mounts. but after they were replaced the car drives like new.