Bossman140

Hopefully someone can enlighten me. I had a feeling my motor mounts were bad on my 2000 E430 4matic. The car needed tires as well so I had them replaced. Immediately after replacing the tires, the small/slight vibration I felt at idle became instantly increased. What is the correlation?

BTW I did eventually have the mounts replaced.

khomer2

Your posting is very confusing.
You replaced the motor mounts after the tires were replaced?

Were the tires balanced when you replaced them?
So the vibrations increased, you say, after replacing the tires.....
And the motor mounts replaced last?

And the resulting vibrations? What is the status of it now AFTER motor mount replacement?

Bossman140

Apologies for not being clear.

Purchased the car in February and felt a very slight vibration at idle only. When stopped at a red light or stop sign for example. Was not very noticeable.

In March, I decided to have 4 brand new tires installed and they were balanced. Immediately upon leaving the tire shop I noticed the vibration was significantly louder. Almost like a rumble. Would stop immediately upon acceleration.

Thanks to the people in this group I figured out that the rumble was from my motor mounts. Had them replaced with OEM mounts specific to the 4Matic and the rumble/vibration is approximately 60% better. The engine mounts were original and in pretty rough shape. I will also replace the transmission mount this weekend.

My question is why would the new tires amplify the rumble? It was barely noticeable with the older worn tires. Just seems odd to me.

khomer2

Thanks for clarify the sequence of events.

I would not think new tires would do something like this.
There is something else that's causing the issue.

Report back when you've completed the R&R of the tranny mounts and test drive.

I would also recommend you do a good visual inspection of your spring perches (as these are well-documented for their failures).

Some good related reading for you here - https://mbworld.org/forums/e-class-w...-solved-2.html

Bossman140

I found it odd as well that the rumble would amplify instantly with the new tires. The tire shop did nothing but lift the car and remove and replace the tires. I watched them like a hawk.

When my mechanic R & R'd the motor mounts he kept raving about what tremendous condition the car was in. The previous owner kept it garaged and only serviced it at a MB dealership. I have almost all the service records.

The mechanic was at a loss as to why the tires would amplify the rumble. I suggested that maybe because they are new, they are firmer and thicker than the old worn set of tires. He said anything is possible. He had no idea either.

Will report back once the tranny mount gets changed.

khomer2

That's awesome.

In the back of my mind, I'm also thinking could it be the flex discs?....

http://www.mercedesmedic.com/mercede...symptoms-cost/

Bossman140

Just had the transmission mount replaced. Car still rumbles at idle. Mechanic thinks it may have to do with the steering rack. Either way, I’m not chasing anything anymore. It’s a 20 year old car that I purchased for very little $$. Gonna just live with it at this point. Consider it a quirk

Bossman140

The mechanic is a tech at a local dealership. He does some side work for extra cash. After consulting a bunch of techs at the dealership this AM the unanimous opinion is that its the axel(s).

You were correct in your suggestion that the issue is not the mounts.

Strigoi

So this only happens when the car is stopped and at idle? If that's the case, the tires, axles or various mounts (aside from the engine mounts) should not be an issue. The engine mounts in these cars are hydraulic. Take a look underneath and see if there's any orange staining. If not, the mounts are fine and not an issue.