Em Bee Lover

I know this has been beaten to death, but I am simply at wits end.

82k miles on 2007 4Matic Launch. Only 21000 on new (revised and upgraded) motor mounts. Trans. mount also replaced.

The steering wheel vibration is really annoying, but the "dead hum/droaning sound" (if that makes sense), at the normal operating rpm has me just stumped. And, pretty darn annoyed, as I am dialed into the sound.

Indi put jack under engine, while on hoist and the the floor jack vibrated like a jack hammer. Removed trans. support bracket. Put jack under it. Floor jack very active/vibrating. Indi thinks new motor mounts needed. Again. He did the last job. I don't wanna kick in another five hundred bucks and not have a fix.

Any guidance on what the hell's happening w/ the vibration stuff? The "droaning" sound is like a muffler/pipe leak, but that's been eliminated. Kind of a "flat", not normal sound.

Pls. help; very frustrated.Thanks.

Em Bee Lover

Anyone there to guide me?

I am desperate, to eliminate this.

Cannot believe it is caused by deteriorated motor mounts, which were replaced less than 20k and three years ago, w/ the latest and greatest released MB mounts.

What else impacts the steering wheel vibration and the dull (sounds like a leaking muffler, but isn't) sound, as I drive? It's always around 16-1700 rpms.

I cannot be the only Launch owner experiencing this, I hope.

Thanks.

Quadcammer

what tires are you running?

Em Bee Lover

Continental Extreme Contact DWS. They have about 15000 miles on them. Don't remember dimensions, but are what OEM specs call for--18"'s etc. There is tire noise w/ any tire, depending on the road surface. That noise is wholly separate of the darn droning noise at acceleration to about 1600 rpms.

Ana side...I also have a pull, more than a fade, to the right. I have had all three other tires/wheels moved to the right front, thinking thrown wire or similar. It appears all tires are solid. Alignment specs are dead on, according dlr. That's also got me perplexed and annoyed.

jwxspoon

Had similar issues when I got my 2008. Took a variety of steps to completely eliminate the vibrations.

First, I had a rim that was just slightly out of 'round'. I replaced all 4 tires and rims, which reduces but didn't remove the vibration. Balanced and rebalanced all wheels. Complete alignment. Finally my tire dealer ordered all new lugs and hub centric rings... that was what ended up doing the trick. The hub centric rings were an inexpensive fix and solved 80% of the problem.

Still had vibration under acceleration though, which progressively got worse. Thought I was losing a transmission or torque converter. Ended up being motor mounts, transmission mounts and some sort of steering linkage.

Drives like a dream today. Hope this helps.

Jeff

zam2000

I also had problem with vibration and low frequency noise.

1. As for vibration: shop after shop keep balancing wheels, and check on brake, yet problem keep happening. I then went to Globe Tire (Manhattan Beach, CA), who did the road force balance. They told me that my front rims were not in perfect round shape. Sent the rims in to have it mold back to round. All vibration problem went away.

2. Noise: lot of shop check everywhere, and couldn't find it. Only happen at 1500-2000 rpm. Lot of "potential" causes: engine mount, trans mount, cat converter, rear axle, tire, torque converter. But no one was able to confirm that if I fix them, the problem would go away. Took the car to MBTech (Monterey Park, CA), the found the rear wheel bearing is bad, not bad enough that you could shake the wheel lose, but enough to make noise. $$300 job and problem went away

marthyh

Did you check the drive shaft(from 'front to back' :is it damaged or dented ?), and its disks( Hardy disks all ok ?..Although that would give a rattling or thumping noise when accelerating)and/or its bearings?

mb1000

i had the same issue for a while. At ~1500rpm in 60mph, very annoying droaning sound came up. I had to gave more gas to down shift as a work around. The issue to me is similar to a manual trans that one did not down shift correctly caused engine to labor. In my case, changed engine/trans mounts did not solve the issue.

Later, I got P0012 and I replaced all 4 cam magnet sensors. The p0012 cleared and droaning went away, too. Checked old magnets, they have some sort of binding / sticking feeling that's why they can't change cam /timing correctly.

To replace magnets, you need to release 3 screws that hold the PS fluid tank (no need to take the tank off) to give just enough space to take out a magnet.

Also, after changed magnets, shift from 1st to 2nd is smooth again as new now (had surge feeling before). That issue looks like TC or trans problem but could be magnet problems too. Bad magnet sensor impacts cam profile / timing.

marthyh

Do you have part numbers for the magnets and how easy is it to DIY replacement?

mb1000

https://mbworld.org/forums/c-class-w...ank-1-a-4.html, Part # 2720510177, $25 each from parts.com. MB uses same parts for many different engines.

only the one behind PS fluid tank needs a little bit efforts.

marthyh

Great info thanks!

Hfdafhx

Driveshaft Carrier bearing