ROADSTIR

Lately, my 2005 E320 CDI has been giving me some serious low frequency vibrations, especially when started cold. It also makes a sound similar to, but much softer than, the noise a diesel truck makes when the "Jake brake" or exhaust break is used. In other words, as I slow down for the stop sign, as the car down shifts, there's this brief rumbling. Vibration is strong enough to make other parts of the car buzz.


Perhaps the catalytic converter? How do I test?

Blitz2639

First thing I would check is the engine and trans mounts.

beejAMG

cat converter issue will make noises like shaking quarters on an empty can. vibrations coming from the engine could mean engine and trans mounts. i would do what Blitz suggested.

ROADSTIR

Thanks for the advice. I'll be crawling under there tomorrow and will report back.

cmh1991

I am having similar issues on a 2005 e320 CDI. When cold starting the car, the car vibrates loudly and after fully warming up and driving the car the vibrations eventually go away. I took it to a local mechanic and was told the motor mounts are worn, but the vibration would still appear while driving the car. Any other recommendations on what could be the issue?

cetialpha5

It's very common for the motor mounts to go and then you get a vibration at idle. Maybe it only really goes away when the car is warmed up and the idle drops so you don't notice it at much. You could pop the hood, start it up and see if the motor ****s around when hitting the gas. The transmission and motor mounts are frequent replacement items. Mostly because MB uses liquid filled motor mounts and while it's very smooth when they're working, once they leak, the car tends to vibrate. Cheaper makes will just use rubber which last longer but isn't as smooth.

rocky472

The engine mounts can defiantly cause excess vibration, especially on a diesel. If you are curious about the repair check of YouTube users LegitStreetCars and MBDieselFreak. I replaced the mounts in my 05 E320 CDI myself. The LH engine mount and transmission are fairly straight forward. Replacing the RH requires jacking up the engine but does not require removing the exhaust. After the repair the, engine was noticeably higher in the engine bay. I included a picture of my old mount and the replacement. Mine had not leaked but defiantly collapsed.

I also have a 2010 E350 gas. The mounts on that car required dropping the cradle. Thankfully that job was done under an extended warranty.

cmh1991

it was the motor mounts. I had a shop replace the motor mounts and the transmission mount on the car and wow what a difference it made. thanks for all your help on the diagnosis.