rosenhauer

I have vibration at idle smooth if you rev it up a bit. I've done the set parking brake/brake rev in drive and reverse and it does lift a bit more on the driver side than the passenger, but still not that much.

Searching the parts sites there seems to be confusion on what motor mounts I need I have a 2012 GL350 and the most common I found are

251 240 30 17 Right (Passenger)
251 240 46 17 Left (Drivers)

Some sites show 251 240 43 17 as a replacement for the Right (P) and others show it as for both yet others say 251 240 43 17 isn't compatible with the 2012.

Yet others list 251 240 32 17 as working for both left and right.

Anyone have insight on why all of the different numbers? is 251 240 XX 17 the basic mount format and the XX some sort of load rating or dampening factor?

Plutoe

To be correct post your VIN!

rosenhauer

4JGBF2FE4CA779810

Plutoe

[QUOTE=rosenhauer;7175924]4JGBF2FE4CA779

You are absolutely correct--see my current post!

rosenhauer

I just looked up those and they are brackets not the motor mounts.

Plutoe

You are correct the most current mount part numbers are L= 251 240 46 17 and R= 251 240 30 17

rosenhauer

Well that's my problem. 251 240 30 17 doesn't seem to exist anymore.

Then you search for 251 240 30 17 it shows that 251 240 43 17 replaces it.



Then if I go to that product page (below) it says it's not compatible with my truck.


So either it doesn't replace it or it's actually compatible... Just need to know what to order

Plutoe

Quite FA-------go here https://www.oediscountparts.com/part...?siteid=215242

rosenhauer

Replaced both mounts and it didn't eliminate the vibration, it was better but not gone. Last week started hearing intermittent belt squeal. Replaced the serpentine belt and vibration is gone. Along with a ticking sound i was worried was a bad injector. There must have been a bad spot in the belt and the noise was the tensioner. It only happened under acceleration.

mefferso

Interesting that it was the belt. Thanks for letting us know what fixed your problem

AMG_Go_Fast

So I somehow managed to remember reading this thread months ago, low and behold I now have a vibration at idle (00 rpms), much better at 750 rpms. Took it to the dealer still under CPO and they said the motor mounts are bad so they will replace them (70K mi)

Q: How the heck do motor mounts go bad? I bought it with 48K miles and dont drive this too terribly hard.
Q: Why would you only feel vibration at idol and not at higher revs?

Anyway I will update the result once the mounts are replaced.
T

wankel8

So what part number mounts were used?
I have a w164 ml500 and 251 240 30 17 is what makes Dundee said for both L and R side.
also, like the op, that part number is almost non-existent.

rmfnla

Motor mounts in my GLK went bad after 32K; out of warranty because I only drive ~6K / yr.

Last time I replaced a motor mount was in a Honda with 175K.

“The best or nothing” my ***...