MZen

Hello,
I changed oil on my R320 and noticed some strange substance droppings on the driveway after that.
This substance does not smell, has oily and very dense appearance and is like nothing I encountered in years working on my cars.
At the same time I got 'Low coolant level' message.
I would greatly appreciate if you share your knowledge of what it is, possible source of leak and how to fix it.



Wet spots indicate position of front wheels, driver side is on the right.
It is slightly bigger in size than quarter.


Underneath pictures show transmission (?) mount on the driver side is covered in the same substance. Actually, there is leak on the passenger side as well, yet not so heavy.

B34chBum

Does the car vibrate noticeably at stop in Drive, or started to do so in the past few months?

I'm not positive of relative location of motor mounts to the drips in pictures
, but know the mounts have a viscous fluid in them and they are at a higher level than what you're looking at.
If they are torn and leaking perhaps this is what you're seeing - I've also not cut one open to see the 'filling'.
I would remove the lower engine cover and have a look upward, there's usually a path to drips.

Re-reading your post - the transmission mount is toward the rear of the trans and there is only one.
It really sounds like blown motor mounts, and if so you would want to replace both,

Out of curiosity, if you go to an indie shop for service - the part numbers for mounts, whether ML, GL, or R-Class all start with 251 (which often designate the model/platform).
Pricing on the R mounts seems to be higher than the others, and I wonder if ML mounts (the most common model) would fit sufficiently well to serve as a substitute.
If anyone could speak to this I'd appreciate knowing...

Racin_fool

this is not from the engine mounts, but it IS coming from the engine mount support brackets between the engine mounts and the crankcase.. It is supposed to be a material that stays in the support brackets but over time with temperature cycling, humidity and all sorts of things, it starts to liquify and drip down the sides of the engine.

So what you need to replace are the support brackets that may or may not come with that same material in them. I have seem them come with and without the material during the many times i have replaced them.

B34chBum

Thanks very much for the info!

Now that you mention, I do recall reading about the mount supports before... Was the liquid intended to help keep the mounts cooler or further dampen vibration?

Also, are the motor mounts as application-specific as the parts listings suggest?
I don't really care if the ML/GL mounts are a little stiffer than ones for the R - but if they were too high or introduced clearance/fitment issues, sure I'd get the correct number.

Racin_fool

the material (when you see it new in some new mount supports) is very thick and spongy.. My best guess is that its purpose is for extra vibration dampening. I have no idea on parts differences between engine mounts, I always just get what EPC tells me and install them.

MZen

Hi guys, thank you so much!
I appreciate your input. Given that I need to replace mount support brackets, how difficult is it to DIY? Any special tricks, tools, sequences of parts removal?
I do have basic and not so basic tools. Yet, little bit scared of MBs.