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#1
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300sd shakes while in park or stopped
I am sort of new to this site, so please forgive any stupidity on my part. I have a 1982 300sd with 250k miles. Just had valves adjusted by mechanic. Car is shaking from side to side while in park or at a stop light. Do I need to replace the engine mounts? I doubt they have ever been replaced. I assume the engine vibration is transferring to the rest of the car. Also the rear end is sitting a little low. Should I think about replacing the rear springs and if yes, then which ones? Should I go back witha heavy duty spring? Would appreciate an honest opinion from someone more knowledgeable than myself.
Others have said - rack dampener which my mechanic wasn't familiar with unless its called something else - I read the old ones had a weak spring and needed replacement, but where is it on the car so I can tell him or do myself? I know I have never run a can of diesel purge through injectors - only in tank. What brand of purge? Thanks for the help. |
#2
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You probibly need both motor mounts, (maybe engine shocks too), and if you do those you should replace the transmission mount also. Rack damper has to due with an idle that rythmicly increses and decreases. Up and down. If rpms are faily steady its not the rack damper.
__________________
Proud owner of .... 1971 280SE W108 1979 300SD W116 1983 300D W123 1975 Ironhead Sportster chopper 1987 GMC 3/4 ton 4X4 Diesel 1989 Honda Civic (Heavily modified) --------------------- Section 609 MVAC Certified --------------------- "He who fights with monsters might take care lest he thereby become a monster. And if you gaze for long into an abyss, the abyss gazes also into you." - Friedrich Nietzsche |
#3
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Thanks bone head doctor
Thanks for advice. The rpms are very steady. I suppose the engine shocks and engine mounts and transmission mount are the culprits. Thanks.
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#4
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Quote:
__________________
Proud owner of .... 1971 280SE W108 1979 300SD W116 1983 300D W123 1975 Ironhead Sportster chopper 1987 GMC 3/4 ton 4X4 Diesel 1989 Honda Civic (Heavily modified) --------------------- Section 609 MVAC Certified --------------------- "He who fights with monsters might take care lest he thereby become a monster. And if you gaze for long into an abyss, the abyss gazes also into you." - Friedrich Nietzsche |
#5
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willrev,
Actually they are engine dampers. They dampem the rocking and shaking of the engine. P E H |
#6
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Quote:
__________________
Proud owner of .... 1971 280SE W108 1979 300SD W116 1983 300D W123 1975 Ironhead Sportster chopper 1987 GMC 3/4 ton 4X4 Diesel 1989 Honda Civic (Heavily modified) --------------------- Section 609 MVAC Certified --------------------- "He who fights with monsters might take care lest he thereby become a monster. And if you gaze for long into an abyss, the abyss gazes also into you." - Friedrich Nietzsche |
#7
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The rack dampener is on back of the IP, next to the oil filter housing. My engine developed that rocking side to side and that was with new motor mounts and engine dampener mounts. Adjusting the dampener bolt did indeed reduce most all the rocking at idle or park.
__________________
'82 300SD - 361K mi - "Blue" "Good judgement comes from experience. Experience comes from bad judgement." listen, look, .........and duck. |
#8
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I can also suggest that the rack dampener pin upgrade will help with the shaking even on an engine that has a steady idle RPM. It seems the spring in the pin keeps the injection rack from oscillating with the natural shake of the engine at idle. I did the engine mounts and shocks first and the shaking was still there - and then the rack dampener pin upgrade took it all out.
On my 1982 300D, I also did the transmission mount replacement. This was the start of my driveshaft vibration troubles on that car. It seems the driveshaft had become comfortably worn in a certain spot, and when I put in the new mount, the whole system was raised back up - and started vibrating. So on my future cars with the same system, I plan to never replace the transmission mount as long as there is still rubber in there and the driveshaft is running smoothly. Ken300D
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-------------------------- 1982 300D at 351K miles 1984 300SD at 217K miles 1987 300D at 370K miles |
#9
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I think I would recommend at least adjusting the rack dampener before looking at replacing the engine mounts. The fuel rack dampener gets worn and can cause exactly what you have.
I is mounted on the rear of the IP. Has a 14 mm bolt head and a 12 mm lock nut. Pull it out and check the tip. Should have a spring loaded rubber point that gives but is firm. If it is compressed and won't bounce you should replace it. Costs about $35. You can order one here on Fastlane. Then thread it back in to about where it was. Start the engine and turn it in until the idle smooths out. You will need to rev the engine as it is turned in. If the engine dies when rev'd, you have turned it in too far. If when all done you think it is ok, then you get in to drive and it won't back away from the garage without dying, you have turned it in too far. No problem, just loosen and try again. Usually they turn in a long ways. You will get the feel for adjusting if quickly. One other thing, you may still have a defective early style in there, it is silver or aluminum color. Newer upgrades are gold. Gold color gets faint after time. Always replace the silver ones. |
#10
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Be sure that the engine speed at idle is at least 700 rpm (750-800 might be even more desirable). If any lower, the engine may shake rather forcefully even if everything is FINE.
The little engine shocks have little effect on engine shake at idle (many OM61x engine don't even have them) but play a BIG role in controlling engine shake at shutdown. The rack damper bolt on the rear of the injection pump WILL allow the engine to lope about every 2-3 sec when it fatigues from age (and ALL of the original silver colored damper screws WILL fatigue eventually) . There is a revised version (gold colored) with a MUCH stiffer spring that will NOT fatigue. This damper controls ONLY the cyclic lope that is a product of the natural resonance of the linkage and rack assembly. It will NOT control other causes of engine roughness! Marshall |
#11
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I'd be concerned that your mechanic (who adjusted your valves) had not heard of the rack dampener screw.
Perhaps you need to find another mechanic (or diy)
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84 300DT Puke Yellow. Totalled after 438,000 84 300DT Orient Red. 169,000 (actual mileage may vary) 2002 Explorer EB (wife's) |
#12
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Quote:
__________________
Proud owner of .... 1971 280SE W108 1979 300SD W116 1983 300D W123 1975 Ironhead Sportster chopper 1987 GMC 3/4 ton 4X4 Diesel 1989 Honda Civic (Heavily modified) --------------------- Section 609 MVAC Certified --------------------- "He who fights with monsters might take care lest he thereby become a monster. And if you gaze for long into an abyss, the abyss gazes also into you." - Friedrich Nietzsche |
#13
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Does this rack dampener info apply to '77 616 eng. also?
......
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Jim '49 170?(donated to church in Darmstadt '58) '58 220S(crusher, after '73 fire[San Antonio]) '72 280SE 4.5 '77 240D '81 300SD '83 240D parts car |
#14
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Since you guys are on the subject.......my '79 300D shakes at a stop sign with the trans in drive, but if I put it in neutral, it smooths right out. I find myself changing to neutral at long lights to avoid the rattles. The Indy that did my valve adjust and general check over after purchase thought my motor mounts and shocks were OK
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'85 300D - 206K (sold) '81 240D - 149K (sold) '03 Jetta TDI - (sold) '79 300D - (sold) |
#15
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Quote:
__________________
Proud owner of .... 1971 280SE W108 1979 300SD W116 1983 300D W123 1975 Ironhead Sportster chopper 1987 GMC 3/4 ton 4X4 Diesel 1989 Honda Civic (Heavily modified) --------------------- Section 609 MVAC Certified --------------------- "He who fights with monsters might take care lest he thereby become a monster. And if you gaze for long into an abyss, the abyss gazes also into you." - Friedrich Nietzsche |
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