82 240D Engine Idle not smooth for a diesel

[airfoill]

I have a question for the group. I have an 82 240D and have noticed witin the last couple of months that during idle, the engine appears to be loping as though an injector was clogged. It isn't bad but I do believe that this engine was idling smoother when I purchased it a few months ago. I have adjusted valves, ran diesel purge, replaced both fuel filters and even went as far as purchased a new set of injectors today and it still has the same symptoms. During high engine speed, the problem disappears. The car only has 106,000. The previous owner had the timing chain replaced a couple of years ago.

Another thing that I have noticed is that before I replaced the injectors today, it would appear to be idling alot smoother after being driven for a while.

Is it possible that a valve could be bad? One thing that I did notice that when I was cranking the engine after installing the new injectors is that the compression strokes appeared even on all cylinders during the starting process. I know this isn't the correct way to do a compression test, but I had a Honda years back that had a bad valve and every time you started that engine, you could tell that one cylinder was weak during the starting process (loping before the start). It just seems that this car has very little mileage to be having valve problems.

Haven't taken it in for injection timing or compression test but that may be my next step. Any suggestions?

Thanks

[airfoill]

One thing that I forgot to say in my original post is that the engine is very easy to start and usually starts within a second or so when I've got the starter engaged. The engine also has plenty of power. The only time the engine smokes (small amount of black) is when I first start it up in the morning. After that it doesn't smoke during idle and very little during acceleration.

[Jim H]

One possibility is the engine damper is no longer functional. (Boy, I hope the 240D HAS one!

The damper is basically a shock absorber which is supposed to dampen the rocking motion of the engine. Imagine that Do a search for "engine damper" as there have been several posts regarding this.

Other posts mention a weak fuel injection rack dampener spring. Search for that also.

Good luck!

BCingU, Jim

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'96 E300D 60k mi (wife's daily ride)
'95 Audi 90 120k mi
'92 GMC Suburban 139k mi
'85 300SD 234k mi (my daily ride)

[123 300D driver]

Are the motor mounts original? I had a similar situation with my 300D. After changing the 100k mi mounts, the symptom went away to a degree. The problem is that the old mounts collapse after a long time and transfer the vibrations to the frame.

[airfoill]

The engine mounts and the small shock absorber mounted on the engine were replaced by the previous owner.

Tonight, I'll try looking for that fuel rack damper screw and see if that works.

BTW, if this doesn't work and I want to check compression, can it be done with a regular compression test gauge by removing the glow plugs and installing the gauge where the glow plugs screw in?

Thanks for all the info.