Hi all -

New to the forum here. I have a 2011 GLK 350 RWD (190k miles!) and am diagnosing a vibration at idle issue when in D or R.

After purchasing the car, I took it to the dealership for airbag recall work and they performed a courtesy inspection. Noticed the transmission mount was collapsed. I replaced it with a Febi mount (https://www.autohausaz.com/pn/11107) but the noise did not go away. I think this did reduce the vibration issue at idle a bit, but honestly can't remember since it's been a few months. It's not completely gone. The dealership did not note the motor mounts (which I'm sure they would have loved to since it's an expensive job). The mounts are not leaking and I have performed a quick engine mount test and they seem to be fine. See video link below.

https://imgur.com/ON8vwUa

What do you all think? Looks fine, right?

I may have forgot to really torque down the transmission mount bolts when performing the swap so I'm going to do that this weekend while I install a new rear flex disc. Does anyone have experience with aftermarket transmission mounts (Febi)? I'm thinking I may just buy an OEM mercedes mount just to be sure, but wanted some feedback first.

 

Febi is a solid brand for parts, use with confidence.

Having said that, if the part itself is Chinesium.... I'd pass.

 

The guibo I purchased is also a Febi part and was made in Germany thankfully. I do remember noting that the transmission mount was not made in Germany (I think Indonesia or India, can't remember). In addition to re-torquing the trans mount, I'm also going to clean the MAF and throttle body this weekend. I doubt it's been cleaned ever. Any opinion on the video I posted?

Anyone here have success changing the motor mounts using this tool?: https://www.fcpeuro.com/products/mer...-baum-00100162'

 

that tool sucks, BUT, it MIGHT work on a RWD. That tool would not work on an AWD truck. There is no room. It def sounds like it is your engine mounts, when the mounts inevitably fail, they cause the vibration you feel at idle. We did this on my friends AWD GLK. Your RWD glk will be much easier. There is a popular video on youtube (nathan?) uses (and sells) that tool on his RWD GLK and he gets it done pretty quick and easy, no pulling axles or removing steering linkage. AWD ones are more involved but not impossible.

https://mbworld.org/forums/glk-class...ml#post7573052

 

I suspect it’s the mounts as well. I’ll clean the throttle body and MAF but I doubt it will do anything. Cheap insurance anyways.

I’ve seen that video and will probably bite the bullet on purchasing the tool. Mine are just beginning to fail so just a minor annoyance at this point. From my research, it sounds like these mounts are a common component to fail - wish an aftermarket company would step in and make a product that will last longer. Thanks for the input.

 

I have a similar issue I am trying to tackle which points to the mounts, but the engine does not move very much like yours when brake torque-ing.

Perhaps the mounts have stiffened due to age, and not allowing the natural, smooth back and forth movement when brake torque-ing. Look at the video below where he shows the before and after towards the end, you'll see the manner in how new mounts cause the engine to move.

 

I used a standard 16mm torque adapter for both sides. Invaluable tool for the mounts.

 

Forgot to update. I replaced motor mounts over the holidays (2019), and things were great. No vibration, everything cured, had that new car feel. 2 years and about 20k miles later, the mounts are beginning to fail. Light vibrations have started to creep up. Can't believe how short these things last - it's basically a maintenance item! I used Lemforder mounts. Luckily I purchased from FCP so lifetime warranty, but am wondering if I should go for Corteco or go OEM. Can anyone speak to how long their mounts lasted, which brand they used, etc?

 

My engine mounts on my W204 4-matic were replaced two years ago as well. For me it's been 29000 KM and while the mounts don't feel exactly like day one they were replaced, they still feel great. My mounts were Genuine.

I'd say light vibrations are normal, though. And of course there are other parts which can also contribute to vibration.

 

Interesting, good to know other are experiencing similar things. I should clarify that the vibrations aren't harsh, but very light and noticeable if you're feeling for them. I suppose it's just that these cars feel incredible with fresh mounts, and anything worse than perfect seems like an "issue" when it really isn't. May look into flushing power steering fluid and replacing container/filter as my power steering system seems to shudder/groan slightly when cold and turning from stationary. But, that's for a different thread.

 

I used Lemforder as well at 88k miles. I'm at 112k miles and 3 years later without any vibrations yet. Don't confuse vibrations that come from the engine periodically. If you have older gas or car is cold there are some vibrations coming through. The engine is very sensitive to old gas, it runs poorly if not driven often.
There also seems to be certain idle speed that engine vibrates ever so slightly more (I can't really tell if that due to gas/temp/or something else). But at 500-600 rpm it's so smooth sometimes you can't tell car is on. I'm pretty impressed given cars age how well it runs.

GLK front brakes /pads is another story. 5k miles on new rotors and I'm getting vibrations under braking again. Next time Genuine MB pads are getting tossed. Total garbage.

 

I ditched the MB pads and rotors long ago, after 3 different sets were replaced before 50k miles (warrantied).

Been running Powerstop rotors with Textar ceramics which have held up great over the last 45k miles and still plenty of meat left on the pads. I did rear rotors and pads not too long ago (they were originals).

 

Our 2010 4matic had both mounts go out right at 100k and with the hassle of the 4matic I just took it into a local German shop. It was $1600 out the door, factory MB motor mounts and transmission mount.

The rear wheel drive ones I'd definitely do myself. There are some good YouTube videos out there and it's not difficult for the shade tree mechanics like me and you.

 

Just ordered the Corteco kit from FCP Euro (decided to replace the still-OK transmission mount, too).

Have a torque adapter coming - couldn't find one that would get here in time in 16mm, so ordered a 5/8" torque adapter.

Now I just have to work out the easiest / quickest way to get the old ones out and the new ones in. Looks like pulling the axles may be the best option, but I'll at least make a stab at figuring out an easier (read "lazier") way to do it. Does anyone have a feel for the limit on how much you can lift / twist the engine before getting into trouble?

The one wrinkle I'm adding is that I've ordered some heat reflective / insulating fabric-like material that I'm going to use to build a cover that goes between the motor mount and the metal "heat shield" that is over it. I figure it has to make some difference in how much heat the motor mounts have to deal with, which is what has to be killing them. And since I'm in Arizona, they're going to have to deal with a whole lot of heat (120°+ from the asphalt below, who knows how much from the exhaust manifold just above).

 

Well, THAT wasn't a lot of fun. ;-) I'd seen other info showing that a whole lot of other things had to be pulled off to swap motor mounts in a 2011 GLK 350 4Matic, and I was sure I could do it quicker and easier.

I was wrong.

I made a few videos during the process, though didn't end up making one showing the process of swapping the motor mounts, as there's already one out there better than I would have made. Mine was going to show an easier way (that doesn't exist). About the only corner I was able to cut was that I didn't have to pull the alternator out of the car, but just dropped it out of the way without unhooking the cables. Here's that video: www.youtube.com/watch?v=Bp4phUxqVtI

But I did find a better tool for taking that dreaded center bolt in and out. I bought a 5/8" (aka 16mm) torque adapter, which is the right length to work perfectly. I did end up modifying it by heating and bending it, and (of course) made a video of that. Here it is: www.youtube.com/watch?v=v1r0UuGaF1A

I did a short video showing the difference between a worn out (mine were!) and new motor mounts, and their effect on the smoothness / quietness of the car. It's amazing how much quieter my GLK is now. Here's that video: https://www.youtube.com/watch?v=W2erbS7bqlU

And finally (and probably most importantly) I worked out a cheap and easy way to (probably) extend the life of my motor mounts. I've read too many horror stories about these things going bad in as short as 10-20,000 miles, and I do NOT want to repeat the process of swapping them out again. I sourced some heat-reflective material that I placed between the (minimal) metal "heat shield" and the motor mount, which lives about an INCH below the exhaust manifold on both sides. It's no wonder that a pneumatic motor mount doesn't last too long under those conditions. My home-brew supplemental heat shield should dramatically reduce the amount of heat the mounts have to absorb, which should prolong their life (hopefully, dramatically). Here's the video showing how I did it (with info on sourcing the material at the end): www.youtube.com/watch?v=qiUfJXsJtgM

 

“I've read too many horror stories about these things going bad in as short as 10-20,000 miles…”

Interesting as the original mounts were still okay at 155,000 miles in our ‘15 GLK. Maybe they made some changes with the M276 engine.

 

Look at post #7 above - if that's a photo of the 2013-onward motor mount, the distance from the exhaust manifold to the motor mount is MUCH greater than on the 2010-2012 models. It's almost impossible to get a photo of how close the two are in the older GLKs.

And of course, it's MUCH harder to get to the center bolt in the 2010-12 GLK's motor mounts. The "unbent" torque adapter just couldn't get the job done because of the angle and the tiny clearances.

 

Just to add a photo that kinda/sorta shows JUST how tight the motor mounts are on a 2011 GLK 4Matic... in this photo, the heat shield has been removed, as well as the nearest mounting bolt. You can see how the exhaust manifold obstructs any attempt to get to / see the top "center" bolt, and why the tool that's needed is so specific...

 

I was looking at the your videos and others, going to be doing this job hopefully sometime in summer, I’ve been putting off for a few years. I’m wondering if the right exhaust has to be removed from manifold or if all work to remove and put in new mount can be done from top and from front once the alternator is removed. From what I’ve seen you are pretty much using the back just to remove the rear mount bolt and the rear heat shield bolt.

 

I honestly have no idea just how much access removing the alternator would give you. The real issue with a 4Matic is getting the old mount out - and the new one in (if there's barely enough room to get the old one out, chances are good the new one - being taller since it's not shot - might be even more fun!).

There really is no option but to pull the exhaust to get the mount out the rear. It's a LOT easier if your car is RWD - I did a video on that (won't bother posting it here - let me know if you need to find it and can't). But that's a couple hour job vs. 10 hours for the 4Matic.

 

FWIW, pulling the alternator out of the way may be a little more involved than you think (I would rather pull the exhaust, having done both)... Of course, if you're doing an alternator swap anyway, it might be an opportunity to save some time.

 

I rewatched that Autorex video you posted, he places the new right side mount through the front at around the 25:12 minute mark, doesn’t looks like he shows how he took out the old one so I’m guessing the same way. The left side I’ll remove the exhaust for sure. Ya, this would be in on 4matic.