85 Mercedes 300D Shaky Idle

Links to the repairs I've done in the past:
Engine Mounts:
• 85 Mercedes 300D Engin...
Valve Adjustment:
• 85 Mercedes 300D Valve...
Compression Test:
• 300D Compression Test
Injectors:
• 300D Removing Injector...
Overflow Valve:
• Mercedes 300D Overflow...
Rack Damper Bolt:
• 85 Mercedes 300D Rack ...
Timing Chain Stretch:
• 300D Checking Timing C...

[@tydale8629]

I found out my shaky idle was from dirty delivery valves. after I cleaned them in a small ultrasonic cleaner with rust remover I got them super clean and put them back in and now my 300sd idle is soo smooth.

[@patriciozavala6291]

Mine do the same since I bought it 5 years ago. I did all that you have done with not too much lucky. Now I'm going to check the vaccum system, I have noticed that in cold weather it shakes much less.

[@mjmcomputers]

maybe I'll eventually get one sorted out. Not too many things left to check.

[@dymsza]

Thanks for this videos my car has similar problems, I think I may start to record my progress too.

[@tyd2281]

When the car is idling touch the tops of all of the hardlines atop of the fuel injectors and feel for how fast they are pulsing. Does one or more have a different pulse than the others?

[@mjmcomputers]

good suggestion, I'll try that

[@johnbower5732]

I put new motor mounts plus,motor mount shocks on my 84 300sd and that fixed my issue

[@mjmcomputers]

Mine ended up being bad new engine mounts.

[@johnbower5732]

@@mjmcomputers glad to see you got it fixed, all these parts are hard to find and most that you do find are of course made you know where.....China.. I try to buy German, or European in general

[@hachemtaleb5721]

hey man thanx for the vdo i'm currently in the same situation i did all what you did, any updates since then? have you resolved the problem

[@mjmcomputers]

The engine mounts I had installed a few months prior had collapsed.

[@hachemtaleb5721]

@@mjmcomputers thanks a lot ill check mine

[@bokosdieselgarage]

Have you pulled the injectors and bench tested them? You mentioned replacing them but if one was leaking or firing incorrectly it could have damaged your pre chambers.

[@mjmcomputers]

I had the injectors rebuilt with new nozzles and pop tested and balanced.

[@matthewgorgoglione5492]

What works best on OM617 Motors are to have your service be, first a valve lash ever 15,000 miles with 10w40 or thicker oil, drain up pump oil and put a thick 40+weight in the injection pump, then idle your Mercedes warm after all filters clean or replaced along with oil in the motor, then adjust IP pump damper at back of pump with a 14mm and a 12mm open box wrench, after motor smooths out, replace or adjust rack dampner, next depressurize fuel an take fuel injectors out and take apart in order injectors and and boil parts for two hours in a pan on the stove and use one drop of dish soap, reinstall injectors at torque, and your idle and power should be back to stock or better🏁🕶️💪😷🔧🛸🏆

[@matthewgorgoglione5492]

Next would be set idle back down with a new rpm gauge for proper readings and turn alda adjust back down for less fuel, next would be to adjust turbo run off spring bolt to 12psi and you'll be smoking tires and good to go as long as you don't break anything on that stick radiator

[@rb.867]

So did you ever find and fix the rough idle???

[@mjmcomputers]

Bad new engine mounts.

[@bokosdieselgarage]

@@mjmcomputersinteresting, what brand engine mounts did you use, that went bad so quickly?

[@adventurousairman]

Mine has a rough idle as well, just drive it!!!!

[@mjmcomputers]

Going to try a few more things and then just drive it if those don’t fix it.

[@Duphondaree]

Yup mines rough but i love my tank

[@rb.867]

I’d just drive it, I’ve had 3 Mercedes’ diesel cars and they all have a rough idle

[@mjmcomputers]

Turns out the new engine mounts I installed collapsed. Replaced them again and it’s smooth.