Easy, 1-Hour (or less) Engine Mount Replacement for W211 4Matic - PeachParts Mercedes-Benz Forum

EricSilver · #1 07-28-2020, 09:54 PM

NOTE: Subject Car is 2008 E350 4Matic -- Sport Edition

We have all probably seen articles and posts instructing us to remove alternators, a/c compressors, even axles to change engine mounts. None of that is necessary.

In the picture below, my engine mount is in plain view, completely accessible through the wheel well. To remove it, this is what I did:

1.) Remove the two 10mm plastic nuts (above the mount) holding the edge of the fender liner. This will let the liner bend enough to more easily remove the mount. Removing the 8mm fastener at the bottom edge of the liner will make it even easier.

2.) Remove the two 8mm fasteners on the belly panel nearest the mount. No need to remove the entire panel. You only need enough room to remove and replace the 13mm hex lower bolt on the mount.

3.) The mount's upper bolts are accessible through the engine bay. Looking down, they are in plain view. I used a 24" socket extension and placed a wobble on the end before attaching the 16mm socket. (You cannot go straight down.) Once loosened, the passenger side upper bolt can be retrieved by hand -- plenty of room to reach down and get it. For the driver side, use a telescoping magnetic grabber to retrieve the bolt.

4.) Jack up the engine with about an inch or two clearance above the old mount. Tutorials say use a block of wood on the jack to protect the oil pan. I did not have one so I used an 8x11 hardcover book with a rubber mat wrapped onto it. Worked fine.

5.) The mounts can be tilted and pulled straight out. For the passenger side, you will need to carefully maneuver under two hydraulic(?) lines.

6.) Insert the new mount sideways though the fender liner, then tilt up. Rotate it so that the pin on the top aligns with the groove in the engine frame above. Position the mount's bolt hole over the hole in the lower frame. (A mirror helps.) Hold it there while inserting the lower bolt and tighten by hand, making sure the aforesaid pin remains properly aligned.

7.) When both new mounts are in place, lower the engine to just above the mounts. Insert the upper bolt, by hand, into the passenger side mount and loosely secure it in the mount. For the driver side, attach the upper bolt to the telescoping magnetic grabber and position it into the mount. When in place, a flick of the wrist will break the magnet free. Then use the 24" extension to loosely secure the bolt.

8.) Lower the engine completely onto the mounts and tighten all bolts.

9.) Replace the fasteners in the fender liner and lower panels. Replace wheels, lower the car, and enjoy your smoother ride.

RobertFini · #2 07-31-2020, 06:33 PM

This was an excellent write-up, Eric - thank you!

Best Regards,
Rob

EricSilver · #3 08-03-2020, 07:49 PM

Without question, this car is proving to be the easiest one (of those I have owned) to work on.

Quote:

Originally Posted by RobertFini

This was an excellent write-up, Eric - thank you!

Best Regards,
Rob

RobertFini · #4 08-03-2020, 09:20 PM

The biggest problem I have with working on mine is that they've switched to some new type of bolt head that my tools won't fit, so I need to go out and buy new tools.

engatwork · #5 08-03-2020, 09:28 PM

Get a set of male and female torx head sockets and you will be covered.

EricSilver · #6 08-03-2020, 09:38 PM

You mean the Torx bolts?

After the rusted/broken transmission mount bolt incident in this thread:
REPOST W/CORRECTIONS: Transmission Mounting Bracket Removal Question

I went to the dealer to get new ones -- all were Torx head vs the original Hex head. I plan to swap the old for new when I do my transmission fluid change this week.

Quote:

Originally Posted by RobertFini

The biggest problem I have with working on mine is that they've switched to some new type of bolt head that my tools won't fit, so I need to go out and buy new tools.

pawoSD · #7 08-05-2020, 03:32 PM

Nice write up.

It looks like the ball joint boot towards the bottom of your strut in that picture is ripped/split possibly. Hard to tell.

Mounts on these aren't too bad, W210 is a super-pain. W126/W123 are because the bolts never want to come loose, but the R129 is suprisingly easy. (same mounts as a W211/W210 but easier to get to)

Having the little stubby 16mm tool to get at the bolts up top makes things a lot easier.

EricSilver · #8 08-05-2020, 07:45 PM

It does look torn; I will need to have a look tomorrow.

Quote:

Originally Posted by pawoSD

Nice write up.

It looks like the ball joint boot towards the bottom of your strut in that picture is ripped/split possibly. Hard to tell.

Mounts on these aren't too bad, W210 is a super-pain. W126/W123 are because the bolts never want to come loose, but the R129 is suprisingly easy. (same mounts as a W211/W210 but easier to get to)

Having the little stubby 16mm tool to get at the bolts up top makes things a lot easier.

EricSilver · #9 08-05-2020, 07:49 PM

Quote:

Originally Posted by pawoSD

Nice write up.
Having the little stubby 16mm tool to get at the bolts up top makes things a lot easier.

In this car, the stubby 16mm tool would have been too much work. The 2-ft socket extension (with wobble and 16mm socket) made short work of the top bolts, from above. Literally took just seconds on each side.

l_turn9 · #10 11-28-2020, 08:46 AM

Amazon has sets of Torx sockets for around $10. The quality may not be the highest but I will seldom use these tools. If your situation for usage is similar this may work for you as well...

mccauleybil · #11 12-26-2020, 10:15 AM

I am interested to buy a 2003 e320 4matic wagon. Any tips before I pull the trigger?