I just finished installing an om617.951 into my Jeep today and got it fired up. I have no idea how then engine ran previously as I bought it from a salvage yard. They said it ran great, 156k miles.

I set the timing to 26 deg during the install. When I got it started, it shakes a lot at idle, rattles the whole Jeep. If I give it throttle, it smooths out really nice. I don't have a tachometer yet so I have no idea what its idling at. Very very faint white smoke coming out of tailpipe. I have the alda hooked up to the intake manifold and teed to a boost gauge . Where should I start on the rough idle / shaking? It is not the motor mounts.

1983 Mercedes-Benz 300SD Sedan - Engine Miscellaneous - Page 1
check for compatibility (engine shock absorber and mounting kit)

It its not the engine mounts. I tightened the rack damper bolt all the way and it helped a little, butt still a lot of shaking

Not trying to be snarky or argumentative but can you explain how you arrived at the conclusion that it's not motor mounts?

I had a terrible vibration at idle on my swap (617 -> 107) and went through the entire gamut of injectors, compression, filters, diesel purge, rack damper, etc. and finally determined that it wasn't the engine after all, but indeed it was the motor mounts. I was thrown off by the reality of how quickly the engine smoothed out with just a 50 rpm increase off idle. I had a secondary vibration between 1500 and 1800 rpm that turned out to be the transmission mount.

Mine was a special situation, though, in that I was using filled motor mounts, and I erroneously filled them with too hard a urethane. Going with a softer mix was the actual solution.

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Current Stable

• 380SL (diesel)
• Corvette C5
• Manx
• Baja Bug
• F350 Powerstroke
• Auburn Boattail Speedster replica

What make model are the engine mounts from? This kind of thing matters as too stiff a mount will cause problems. Also aftermarket urethane mounts might as well be solid as they are way too stiff.

This engine might be external balanced, RE: there is a offset weight on the flywheel / flex plate / torque converter. Did you new setup take this into account?

They are Westar engine mounts. If it were the flywheel, wouldn't it get worse as I increase throttle? Also, could it be timing?

Are the mounts for the Mercedes engine or some other mount adapted to your needs?

Vibration can come and go depending on RPM ( like an out of balance tire that is smooth at some speeds. ) without being able to see / feel / hear the motor I can't say if the flywheel is the problem or not.

What year / model Jeep ?

Have you ever run a 4 or 5 cylinder diesel before? Diesels with few cylinders tend to vibrate alot.

If the idle is set too low vibration will be worse, perhaps yours is just running too slow.

those are cheap chinese ones. a friend of mine used those on his TD once; they totally collapsed in ONE day! since they totally collapsed the fan blade chewed up the fan shroud too. get OEM ones or Lemförder; the Lemförders are rumored to be made by the same company as the OEM ones

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1983 300SD (daily driver)
1991 420SEL (work in progress)
1979 300SD (future replacement for 83 SD)

RIP:
1983 300SD (totalled)
1986 420SEL

Haha I know better than to buy cheap crap, but I did anyways... Guess I will order the lemforder ones and see if they help. I will also replace my tranny mount.

I just drove it around the block for the first time. It was incredibly sluggish. I could floor it and the throttle response was very slow. Could this be timing?

I would say valve adjustment, new filters if you havent already, and clean out the banjo bolt and swithover valve and lines going to all this. The alda should have a line going to the swithover valve i believe the bottom (from memory). If its got no power that has nothing to do with your motor mounts. Could be restriction from the things i listed and check your cam timing as well. It could make a world of difference.

As for the shaking, the Rack Damper bolt was turned almost all the way in, i turned it the rest of the way and the shaking got a little better. I then changed my transmission mount last night, it was completely rotted out. That make the shaking a little bit better as well. But it still shakes a bit. The rack damper bolt may need to be changed.

I do not have a switchover valve. The alda connects directly to the intake manifold. I do want to adjust the valves. I also need to check the cam timing. I had actually started the motor for a very brief second when it was in my garage right when I got it, before i took everything off and changed gaskets and seals, when it actually fired up, a huge cloud of black smoke came out the exhaust. Now, there is no black smoke whatsoever, not even at WOT.

hey mate,

first I would never believe that some Merc has arrived to salvage yard with
only 156k... so you also have to assume that is actually closer to 300k.

I would go for higher idle rpm (turnigy - hobby king IR, 10 bucks well spent)
or you can go by sound..while I was waiting for my IR to arrive I went
to youtube and listened good running 300sd.. memorise the cla-cla-cla
sequence and adjust according... well if you go over 1000 rpm you might be
in trouble

adjust idle only warm,do not over tight the lock bolt...

engine mounts are must,..and what tranny did you mated with om617?

few guys reported 26 deg as unusable,back to 24,everything cool again ... (tired IP?)

cheers
.

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w126 500SEC gen II euro, powered by OM617 turbo stolen from 84 300SD 2.88 diff,EGR blinded
next wish/project: w114 coupe OM603 powered