I'll be brief as I can.

1) I've been off the forum b/c my 300D has been trouble free for more than 3 or 4 years.

2) Point of thread, my brother wants to fly me out to California to look at his CD w/ 130K miles.

3) Says that when cold, it will attempt to die, as in shudder violently, when coming to a stop but it does not die. Original cold idle after start if fine. Then goes bad when coming to a stop after driving a bit.

4) After achieving running temp, the problem goes away. Hot, there is no shudder when coming to a stop.

5) He can cruise at highway speeds just fine w/ no odd sounds or vibrations.

6) He says that it has a slight nailing, but I don't think he knows what nailing really sounds like.

7) He has a mechanic that says the machine needs a new engine.

8) He, my brother says that the problem is getting worse, but I think the issue may be the same just w/ ruined motor mounts that exaggerate the issue.

-- Linkage and idle has supposedly been adjusted correctly
-- Injectors 1 and 5 have been replaced and supposedly made an improvement but the guess is that something is still wrong with #1 and maybe a slight issue with #5
-- Prechamber was replaced, last effort by mechanic, on #1 and made no difference
-- Mechanic says that the engine needs to be replaced
-- No comp or leak down tests have been performed

Essentially I am sounding off you guys to get ideas before I go out to there. I know it's not easy to diag when I have not driven the car and you guys have no videos.

All ideas and insights are welcome.

Hard to tell about the idling issue but does not sound like a bad motor to me. Did they run a compression test? Might need to change mechanics.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Consider doing:
1. Cold compression test,
2. Cold valve adjustment,
3. Repeat cold compression test,
4. If compression is ok, a diesel purge injector cleaning,
5. Check all mounts as you mentioned,
6. Check crankcase blow-by, at 130K it should be ok.

Can your brother send you pictures of the old mounts? Can he soak the bolts on the mounts before you arrive?

Good luck!!!

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"Rudeness is a weak man's imitation of strength" - Eric Hoffer

Start with basics, have you changed filters?

Had a situation that kind of reminds me of this with an IDI diesel genset I was messing with after Irma...

Would start and run beautifully. But would randomly shut down on underspeed at odd times. Sometimes it would shut down time after time, a few minutes apart... Sometimes it would shut down after 1-2 hours. Sometimes it would run 12 hours or more with heavy load.

Filters helped a bit. A supplemental fuel booster pump (the engine is installed on top of the fuel tank, and didnt have a lift pump) resolved it completely.

So Id want to ensure that the filters on the engine were new (and leak free), then the fuel tank strainer, then ensure that there is sufficient fuel lift.

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Current Diesels:
1981 240D (73K)
1982 300CD (169k)
1985 190D (169k)
1991 350SD (113k)
1991 350SD (206k)
1991 300D (228k)
1993 300SD (291k)
1993 300D 2.5T (338k)
1996 Dodge Ram CTD (442k)
1996 Dodge Ram CTD (265k)

Past Diesels:
1983 300D (228K)
1985 300D (233K)

No compression or leak down tests have been done and the mechanic says he needs a new engine??
Sounds more like he needs a new mechanic!

Ditto the basics. Fuel filters, including the tank screen, and then a valve adjustment. Also, check linkages as the rod length may be placing the injection pump into near shut off.

__________________
Sam

84 300SD 350K+ miles ( Blue Belle )

Sorry for the delay, and thanks for the responses. My father had a medical emergency and I had to leave town.

I agree on the comp and leak down test. Those should have been performed first. I am looking around for the proper tools in the case that I do fly out to see the car.

--Valve adjustment has been recently performed, if I go out I will check it.
--Fuel filters have been replaced
--2 new injectors but no purge, I may do one depending on what I find
-- Mechanic replaced the prechamber on #1 and it made no difference
--I don't know about the nailing and have hazy information, but cracking the fuel line on # 1 prior to prechamber, quieted the engine. Either my brother or the mechanic said it reduced nailing.


I will aim at getting a good video and some photos, but it will be a while since I am out of town.