Just audio in the youtube. It doesn't sound like a bearing. Could be a valve needs adjusting, but those are usually more of a tapping sound. Anyway, that is an almost annual task so do it. I doubt anything bad like a crank bearing or cracked piston. Most likely it comes from a bad injector spray, one streaming or leaking. Unlikely the leaking fuel causes the sound.

While idling, unscrew the top tube nut on each injector in turn, just enough to relieve the fuel pressure and disable the injector. The engine should shake badly with each disabled. The one that makes the knocking disappear is the culprit (or else an internal problem with that cylinder). Anyway, smart to pop-test and adjust all 5 injectors. Insure the place does an "as found" report, noting any bad spray patterns or leaks.

Gotcha.

I picked up some injectors from the parts yard to be able to have more to play with. I probably did a dozen injector swaps/rotations last night, and couldn't get rid of the knock altogether. Though, I definitely got the knock to leave the 1st cylinder and move elsewhere and get quieter. Kinda trying to polish a turd with 9 crappy old injectors, but hey, I think it confirmed the issue. I definitely think a valve adjustment is in order too. Got the gasket in the mail. Now just deciding whether to rebuild with new nozzles or what.

Anyone know of a good diesel servicing shop in Atlanta?

there was a guy on this forum,he had good prices I bought a spare set and mailed to him,took about a week,and had them back,with Monark nozzles

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1999 w140, quit voting to old, and to old to fight, a god damned veteran

Do you have a name? I sent a PM to the guy referenced earlier in the thread.

And here's an upload of how the engine sounds now:

https://www.youtube.com/watch?v=oHvQjM_UXtc&list=UUNIdhnnuQt1JqOC7uYjv9Cg

Knock is still there, but not as loud.

Are you able to determine if it is coming from a particular cylinder?

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Greazzer

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84 300D, 82 Volvo 244Gl Diesel

Greazzer for injectors. You can also do them yourself and mail them to a member with a pop-tester for pop-testing. Eatont9999 will pop-test injectors for you if you pay return shipping.

@Diesel911: Do you need to replace the injector heat shields on the swapping around or is it OK to run for a brief while with and old heat shield? What is the problem of running old heat shields?

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"Senior Luna, your sense of humor is still loco... but we love it, anyway." -rickymay ____ "Your sense of humor is still loco... " -MBeige ____ "Señor Luna, your sense of humor is quite järjetön" -Delibes

1982 300SD -- 211k, Texas car, tranny issues ____ 1979 240D 4-speed 234k -- turbo and tuned IP, third world taxi hot rod

2 Samuel 12:13: "David said to Nathan, “I have sinned against the Lord.” And Nathan said to David, “The Lord also has put away your sin; you shall not die."

Using the 'crack' test, it's 3 (closest to windshield) now. So I was able to get the knock to move all the way across the engine. I got 4 injectors from a 240D at the parts yard and can't find a knock-free combo. Knock goes away after driving a few minutes. It's definitely better than it was.

Greazzer's been PM'd.

That's not a bad idea. Do you know if Eatont9999 does calibration of them as well if they're off? Is there a member who can do that?

I don't mind replacing nozzles myself, but the tools are a barrier to entry.

I will note, I haven't replaced the heat shields in all this injector swapping. They could be another variable.

Replace your fuel lines with original braided fuel hose from your MB dealer. Cheap..
I have found that over time once a fuel line issue was resolved that the injector noises (knocking) will disappear. It might take a week or 2.
Not sure why..just my experience.

If not, the you need to rebuild your injectors, replace the sealing rings, and wait to let them settle in.

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Western NC
1987 300SDL W126 Turbo Diesel 335,000 + miles
1976 300D W115 275,000 miles+

In general as the Engine warms up the Fuel burns better so it tends to knock less.

When I pulled My original Injectors I found the Nozzles at 198K were shot and the little passages in the Injector Pintel were plugged solid with Carbon.
Most of the Injectors I pulled from the Junk Yard were also in the same condition.

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84 300D, 82 Volvo 244Gl Diesel

240 injectors have a different (lower) pop pressure, you'll need a few shims inside the injector body to get the proper pressure.

The attachments are from the 300 D turbo FSM.

Attached Thumbnails

   

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Found the info for a 240, a 616 engine.

Attached Thumbnails

 

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That might explain it!

I saw 300D and 240D injectors were the same, but didn't know they were calibrated differently. Thanks for those charts.

You're welcome.

Note a 300 D non turbo, a 617.91 has the same operating pressure as a 240 D.

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