1984 300D 185,000 Miles.

Have any of you had this problem? I noticed for the first time last week that my car is "hiccuping" or missing when warmed up. Yet it is totally smooth when first started (and stays smooth for short trips). Any ideas where I should start trying to find and fix the problem?

Thanks,
Jeff

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1984 300D "Brown (and Blue) Betty" Over 200k but the odometer isn't counting

Honest guess is injectors but look at those after you do a diesel purge and vavle adjustment.

Try valve adjustment, fuel filters and air filter change.
If that doesn't help, have your injectors pop-tested. A diesel purge isn't likely to help anything if they're bad enough to be causing this.
If they're spitting or not to correct bar, do a rebuild.
If that doesn't help, try the rack dampener pin.

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Sounds like the rack damper bolt to me. Try adjusting it a bit and see what happens.

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I think of the rack dampener as something to adjust after you're sure the injectors, valves and filters are up to spec. Otherwise, it might just cover up symptoms of something that would be reducing efficiency and power also.

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Ditto.

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83 SD

84 CD

this is along the lines of what i was thinking, though i did not consider the rack dampener. I thought perhaps the filter was getting old due to the power being slightly less when the tank gets low - a recent development. and seasonal valve adjustment is in order I suppose. i'll report back in a couple of days with results from these attempts.

though i've used dieselpurge in the past I went with 44K recently. plus my fuel has never dirtied in the glass jar during a purge like some peoples supposedly do.

thanks again for the help.

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1984 300D "Brown (and Blue) Betty" Over 200k but the odometer isn't counting

Injectors, and valve clearences don't generally cause rough hot idle and smooth cold idle in my experience. They affect running at all temps and especially cold starts and cold idles. Thats not to say that adjusting the valves is a bad idea. It's a good place to start. You had already suggested it, I was adding other things that cause hot rough idle.
The rack damper bolt can be checked for free and done by any DIY'er. While injectors generally have to be taken somewhere and checked. You can still inspect and try adjusting the bolt.
When the bolt is removed and depressed there should be quite a bit of resistance. If not the bolt is worn out. And if the bolts in in good shape, and adjusting it makes no difference then there could be injector issues.

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Not to beat a dead horse, but here's the order:

1. If the last time you adjusted your valves was more than 10kmi ago, do that first.

2. Screw in the rack dampener bolt with the engine hot, idling, and shaking until it stops rocking badly, or shows improvement to your satisfaction.

3. If it still has a rough idle, maybe pull the injectors and look at the nozzles. You are looking for excessive carbon buildup on one or more nozzles. Make sure you have a full set of NEW injector heat shields on hand. You can't re-use them.

4. If nozzles are suspect, look into getting them checked out. There are people here on the forum who will do it for you.

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99 E300 Turbodiesel 100k

Is there a rack dampner bolt on a 602 300D 2.5Turbo engine? I'm having similar issues, but just replaced the injectors with a fresh set of Bosch injectors bought from thebenzbin.com

Here is my thread about rough idle in case someone else with a 602 2.5Turbo runs across this thread in the future.

1990 300 W124 2.5 Turbo Running worse after attempted Tune up

If someone has not mentioned it already.
If you think it is an Injector loosen one Injector Hard Line Nut at at a time and re-tighten and see what happens.
Loosening the Hard Line Nut on an Injector that is good should cause the Engine to shake even more. (You also could watch the Tachometer; the RPM should drop when the nut on a good Injector is loosened.)
Loosening the Hard Line Nut on an Injector that is bad should cause little or no change. As with the above if you watch the Tachometer loosening the nut on a bad Injector will show little or no differance in RPM or at least noticably less than when a good Injector nut is loosened.

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84 300D, 82 Volvo 244Gl Diesel

How do you keep from diesel from spitting all over? Is there a refined trick, or simply try to keep a rag between your eye and the hard line nut? Any way to keep fuel from running all over the block too?

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1990 300D 2.5 Turbo 150k miles
1999 F250 7.3L Powerstroke 225k miles 22mpg
Intro Thread

My '83 had the exact same symptoms. The cause was a small air leak in the fuel supply line. It would start just fine and run smoothly when cold. Once it hit 80 degrees the bucking started.