W126 Mercedes-Benz 300SD - How to Replace Engine Mounts and Shocks on an OM617 Turbo Diesel

#impalamansgarage1
In this video I go through the complete process of replacing the
engine mounts and shocks on an OM617 turbo diesel in a W126 300SD.
Notes:
Yes you can easily get to the top of the passenger side mount from the engine bay. However due to the fact that things just don't line up in the universe the way folks think they ought to, you'd be crawling around on the ground and hauling yourself over into the engine bay a 1000 times. I'm not going to do that. Installing bolts from a blind spot while standing UNDER a car is preferable.
EGR: Note that the EGR vacuum throttle switch on the valve cover has been removed and the EGR vacuum lines are capped at the EGR valve. I plan to remove it.
Parts:
Engine Mount:www.pelicanparts.com/More_Inf...
Mercedes-Benz Engine Mount - Lemfoerder 1084402
(Made in Germany)
Engine Shock: www.pelicanparts.com/More_Inf...
Mercedes-Benz Engine Shock Absorber - Stabilus 113 5DL

[@Contantq]

Its important to keep up on engine mounts. I picked up a 1981 300sd southern rust free car last week from a salvage yard. The mounts were gone in it. Today I removed them, passenger side had not collapsed just cracked rubber, easy fix. The drivers side, was completely gone with most of the rubber missing or turned into jelly. That shield is important to keep a diesel fuel leak from dissolving the rubber. Since it had been run without a good mount, metal fatigue caused the frame location to wear away the mounting area for the entire mount breaking out the bolts holding the mount to the frame. That area will need to be cut out and a new section welded in. Not too bad of a job as I have all the frame section from another carcass I saved.

[@johnwight6041]

You have done so much work to this 300SD it must be mint now! Love these videos really helps with my w116

[@ImpalamansGarage]

There are a few major things that still need doing but it's pretty good.

[@bradalloway3232]

It is easier to get to the 6mm bolts with the shields out of the way. Do drivers side then passenger side. Reassemble: The 6mm attached first then shields. then 8mm long bolt goes right in when engine is lowered. Otherwise the drivers side inboard 6mm will be a huge pain.

[@k.j.g.9601]

Okay, these are the best instructional videos on these 617 (I have an 84 w123) straight forward, funny and practical. I am planning on doing these in the next few months. Your whole front end looks new, did you change all of your suspension?

[@ImpalamansGarage]

Yeah I rebuilt the front suspension months back. I made a video series on it. Check em out!

[@libertyanunion]

Great video as always !

[@wernerdanler2742]

I never went after the mounts on my 123 but replaced the shock. I only found one and it was at the back top of the engine. I busted off one of those little bolts on top and could not get at it to extract it so just put the new one on with just two bolts. New mounts probably would have helped smooth it out since they were probably original to the car. It had 280k miles when I sold it. I still kick myself for that.

[@user-ld3zb7vu4h]

👍👏

[@Johnathan_Waters]

That secondary swaying motion of your engine means that there is a cylinder pressure imbalance. In this case, you should see it worsen slightly higher up in the revs (at a fast idle), and then smooth out completely the higher up you go. It's usually being caused by bad injectors. Make sure you balance them with a pressure tester before reinstalling them with new nozzles!! Have you done a compression test? Might be time to look at injection pump timing/timing chain (for possible stretch), etc. It also would be a good idea to pull out the prechambers and inspect/clean everything up. Oh, and if you haven't done it already... "Diesel Purge" by liqui moly is your friend. Cleans out the injection pump internals like no other.

[@ImpalamansGarage]

The engine runs perfectly all throughout the rpm range. There is just a very gentle rock felt at idle that comes and goes depending on how the stars are aligned. 😂 The injector nozzles are brand new however I did not "balance" them. All of them have around a 1mm (a guess) shim on top of the spring. I've not confirmed the exact depth however. I probably should have balanced them when I installed the new nozzles but I didn't want to mess with it. A compression test will be in the cards at some point. That's a good idea for any engine but this car runs very well and I take it on weekend road trips so my motivation for that is minimal. I would not mind removing the IP and sending it off to a pro for some massaging to beef up the performance. All good feedback. Thank you!

[@ImpalamansGarage]

I am quite curious about the prechambers. I recently bought the removal/install tool for that.

[@Johnathan_Waters]

@@ImpalamansGarage You don't really need to remove the pump, just check the timing using the drip method (in the manual). Also I would change the Rack Damper "Pin" as a matter of course. The internal spring can get slightly fatigued and cause the rocking as well. It very well may help you if your issue is only slight. Balancing the injectors is key to smoothnees.

[@ImpalamansGarage]

@@Johnathan_Waters Already replaced the rack damper pin.

[@Johnathan_Waters]

I will be watching for updates on progress!!

[@frigofrigo3875]

Hi Can you please send me a link to your previous video for engine mounts replacement, I can't find it ? Thanks

[@ImpalamansGarage]

kzbin.info/www/bejne/bYDOeXV5rLyXsK8

[@Johnathan_Waters]

What brand mounts did you install? I've found the best ones to be (unsurprisingly) either Genuine MB, or Lemforder. There are different rubber hardnesses for different engines, and I normally order mounts for a 1990 560SEL or similar for any car that uses that type.

[@ImpalamansGarage]

Lemforder

[@syedjamshaid3119]

Thanks for such detailed videos. What's the thing you used to hold the shock so you can loosen the bolt ? I can't find the name of it and I need it.

[@ImpalamansGarage]

Needle nose vise grips.

[@syedjamshaid3119]

@@ImpalamansGarage thank you!

[@yukselbalci6913]

I would like to do the same job on my car but what are the torque specifications to apply on bolts of engine mount rubber and shock absorbers?

[@ImpalamansGarage]

The two screws holding each mount to the car frame are 30 nm. The screw holding each engine mount to the engine are 70 nm. These torque settings are really not that crucial in my opinion. As long as they are tight, it will be fine. If you get the long bolts too tight you will have a very hard time getting them off the car one day.

[@yukselbalci6913]

​@@ImpalamansGarage Thank you for your reply and the videos...very helpfull for me!

[@hakosama]

How long did it take you do this work?

[@ImpalamansGarage]

It all depends on how easily the engine mount bolts can be broken loose. This job takes several hours. I would plan for an entire day if I were doing this at home. The engine has to be raised and lowered and the holes may not line up properly so expect complications.

[@hakosama]

Thank you. I'll stick to the simpler jobs.