95 e300d roaring noise during acceleration - PeachParts Mercedes-Benz Forum

connerm · #1 07-31-2009, 06:14 PM

230,000. There is this loud roar in the cabin when I'm accelerating over 50 mph. When I gently press and depress the accelerator pedal at, say, 60 mph, and I'm just between coasting and accelerating, I can make the sound happen. I was coasting down a long hill at 65 and it was smooth and quiet. When I just touched the pedal, noise came back. Its getting pretty loud in the cabin since the last month or so, but all three of us noticed it today. Had the flex disks replaced a couple of years ago. I've had MB inspect and do the $300 trans service every 30k miles since I've owned it (bought it at 110k). It doesn't sound like a wheel bearing growl, and I can't seem to tell if the noise is coming from the front or back of the car. Any ideas?

babymog · #2 07-31-2009, 07:07 PM

Clutch fan seized and on all the time?

connerm · #3 07-31-2009, 08:20 PM

that's a good darned idea. I replaced it a few months ago with one from the dealer. How can I check it? I know when its bad cause it spins.

Bio300TDTdriver · #4 07-31-2009, 08:26 PM

Quote:

Originally Posted by connerm

that's a good darned idea. I replaced it a few months ago with one from the dealer. How can I check it? I know when its bad cause it spins.

1. Start car.

2. Open hood.

3. Depress stop lever.

If the car is cool, the fan should spin for several seconds. If it stops right away, than it is locked up all the time. That is the reverse of the usual failure, but I suppose it could happen.

connerm · #5 07-31-2009, 08:34 PM

Will check at daylight. What else might it be?

Jeremy5848 · #6 07-31-2009, 09:46 PM

Motor mounts?

TMAllison · #7 07-31-2009, 11:11 PM

I vote for the fan clutch.

When temp is less than 100C or so and its free wheeling you can stop it with slow steady pressure of your finger tips. When locked up and howling with every little increase in RPM you wouldn't dream of touching it.....

matthias08 · #8 07-31-2009, 11:51 PM

mine kinda does this too....

connerm · #9 08-01-2009, 05:12 AM

New motor mounts about 30k miles ago.

connerm · #10 08-01-2009, 02:45 PM

Khumo tires have 34,000 on them and I'm beginning to think the tires are causing the noise. I paid close attention to it today and accelerating past 45 mph, the sound is strong, then past 50 it smoothes out. Accelerating past 60 mph the noise comes back. I'm not feeling any vibration in the steering wheel, but I have a feeling its the tires.

Bio300TDTdriver · #11 08-01-2009, 03:03 PM

Quote:

Originally Posted by connerm

Khumo tires have 34,000 on them and I'm beginning to think the tires are causing the noise. I paid close attention to it today and accelerating past 45 mph, the sound is strong, then past 50 it smoothes out. Accelerating past 60 mph the noise comes back. I'm not feeling any vibration in the steering wheel, but I have a feeling its the tires.

So the fan clutch was not locked up when the engine was cold?

connerm · #12 08-01-2009, 04:49 PM

No. Fan clutch was not locked up this morning with engine cold. I would have been happy to find it locked, but pist cause I just bought it from the dealer. I bought one from ebay a couple of years ago, but all the juice leaked out of it. I'm ready for new tires.

Johnhef · #13 08-01-2009, 06:24 PM

Kumhos are cheap and a decent tire (I have had a few sets of their slicks)but yes that could very well be a source of your noise. Turn the wheel out and look at and feel the edges of the tires for uneven wear. It may even be bad enough to see it.

connerm · #14 08-02-2009, 11:48 AM

That's a good idea John. I'll check em out. These tires had the Hunter Road Force mounting and balancing when new, but I know some of the wheel weights are gone.

connerm · #15 08-06-2009, 07:50 PM

Ok. New Michelins today and the noise is still there. When I'm coasting, the new tires feel good and sound quiet. The noise I'm hearing happens during acceleration from 35mph and above. I was cruising at 70 and when I accelerate, even a little, this loud, low buzzing vibration noise fills the cabin. Buzzing, vibration is really loud and definitely not right. Could it be a trans mount? Could it be something in the exhaust system? Running out of time because I leave for Knoxville next Friday and I don't want to have to drive the Taurus.