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GC1234
06-20-2019, 09:32 PM
i can’t trace this leak above where the motor mount attaches to the block, is there such thing as a motor mount block leak? Pictures best describe what i have going on. 1st pic is the passenger motor mount and leak is on the back bottom side. 2nd pic shows close up of leak, 3rd pic shows top of motor mount with no active oil trail. Note. All pictures are rotated 90 degrees counterclockwise i believe.

doug022984
06-20-2019, 10:43 PM
is it just me or does it look like there's some sort of gasket material between the motor mount and block at the bolt that has the leak in the 2nd pic? You could probably get away with pulling just that one bolt without compromising the engine support just to see if it starts spewing oil everywhere from behind that bolt...

GC1234
06-20-2019, 11:04 PM
is it just me or does it look like there's some sort of gasket material between the motor mount and block at the bolt that has the leak in the 2nd pic? You could probably get away with pulling just that one bolt without compromising the engine support just to see if it starts spewing oil everywhere from behind that bolt...

I see what you mean, in a perfect world i assume that bolt just screws into the block and when removed it wouldnít typically leak oil, am i right?

So someone probably over torqued it or cracked it somehow and did a crappy repair job...

Bobnoxious
06-21-2019, 12:05 AM
Are they oil filled?

https://www.google.com/amp/s/www.benzworld.org/forums/w164-m-class/2883697-grey-goo-oozing-my-engine-supports.html%3famp=1

GC1234
06-21-2019, 12:14 AM
Are they oil filled?

https://www.google.com/amp/s/www.benzworld.org/forums/w164-m-class/2883697-grey-goo-oozing-my-engine-supports.html%3famp=1

I read a few articles on that, dunno if t1n’s have it. I have 2006 om647

Aqua Puttana
06-21-2019, 12:49 AM
The engine mounts are conventional.

Is the fluid seeping from under what appears to be a tar like coating? In the first picture it appears that there are other similar wet spots. Top center and center right.

:cheers: vic

GC1234
06-21-2019, 01:05 AM
The engine mounts are conventional.

Is the fluid seeping from under what appears to be a tar like coating? In the first picture it appears that there are other similar wet spots. Top center and center right.

:cheers: vic

Iíll have to figure out what that dry tar coating is, if anything. As for other leaks, there are none directly above the motor mount (picture 3 kinda shows but i can confirm) the one in front of it is from the turbo oil return/or possibly dipstick, my guess is the former and Iíll be getting the grommet and taking out the alternator to confirm. But this motor mount issue is what has me worried.

GC1234
06-21-2019, 01:08 AM
I currently have a cherry picker at my disposal because i was repairing a crack in the bottom of my oil pan (see other post) i assume i can diagnose this issue by removing the motor mounts, lifting the engine and removing that bracket from the block. But I’m hoping to figure out beforehand what I’m getting into.

lindenengineering
06-21-2019, 01:17 AM
Before getting all drastic.
Remove ONE bolt, clean threaded pocket with a dose of brake cleaner, do the same with the bolt.
Once dry apply blue loctite generously to the bolt thread and re-insert the bolt & torque up . Continue one by one doing the re-seal, finalize with a clean up & test .
Dennis

GC1234
06-21-2019, 01:25 AM
Before getting all drastic.
Remove ONE bolt, clean threaded pocket with a dose of brake cleaner, do the same with the bolt.
Once dry apply blue loctite generously to the bolt thread and re-insert the bolt & torque up . Continue one by one doing the re-seal, finalize with a clean up & test .
Dennis

I will definitely start with that, thank you! But for curiosity, do you have an idea where the fluid would be coming from? Cracked threading in the block?

Bobnoxious
06-21-2019, 02:17 AM
I read a few articles on that, dunno if t1nís have it. I have 2006 om647

I dunno either, just askin.

Bobnoxious
06-21-2019, 02:18 AM
How long of you had the vehicle?

lindenengineering
06-21-2019, 02:41 AM
I will definitely start with that, thank you! But for curiosity, do you have an idea where the fluid would be coming from? Cracked threading in the block?

Engine oil vapors congealing on the outer surfaces plus some metal particles.
Dennis

GC1234
06-25-2019, 02:31 AM
Thanks to Dennis for talking me off the ledge and working through a simple solution first. Pulled the bolt, brake cleaner liberally all over, reinstalled and I just so happened to have a 600 mile trip over the weekend. Flawless performance (other than 2 LHM due to a short to ground O2 sensor issue I've known about...working on that next) and no leaks on the motor mount to show.

Thanks again!!