[SOLVED] See post #13 below for what I did to fix it

I could really use some help chasing down idling issues with my 83 300TD, I am feeling stuck.
Here's the run down...

On cold start, it seems like it's intermittently nailing/ soft-missing. Sort of sounds like the paint mixer at Home Depot. (I've linked a video of a cold start below) It's much louder under light throttle. When the engine reaches operating temperature the clattering is gone, but the engine will shake back and forth, slightly rocking the car, sort of like a soft miss on one or two cylinders. It lightly smokes at idle and smokes a lot under acceleration (light gray smoke), but it doesn't seem down on power.

Here's what I've done so far, with little or no improvement...

• Valves adjusted (I've done it twice. Once again just to make sure)
• Fresh filters
• Compression test (380-390 on all cylinders)
• New glow plugs (No issue starting on the first crank, even on the coldest of days)
• Rebuilt injectors with Monark nozzles (balanced and tested at 135 bar)
• New gold style rack damper bolt (No difference no matter how far its threaded in or out)
• Cleaned the delivery valves (They were a bit corroded) and used new crush washers
• Tried a few different injection pump timings with the drip method (23* was worse, 24* no improvement, 25* maybe a little better but not much)
• Checked for timing chain stretch (only 2*) and chain feels rock solid
• Motor mounts and shocks have been replaced less than 10k mikes ago
• Replaced the hand primer pump with a metal Monark one
• Adjusted the ALDA back to stock settings (No difference, still lots of smoke under acceleration)
• Checked the intake path and turbo (9PSI by 2300 RPM)
• EGR delete (No change before or after this)

I've got a new set of delivery valves and springs on the way to see if that helps since they were a bit corroded.

I've got paperwork that the engine and injection pump were replaced at 230k miles by the previous owner. The only thing that stands out as odd to me is that the injection pump doesn't have a Mercedes part number stamped on the info plate below the Bosch part number like usual. The Bosch part number on the pump also doesn't seem like a common one (0403245012), but that's been a dead end for me, it looks like a normal MW pump. Could it be a pump from a NA engine?

So, before I go an order a rebuilt injection pump, let me know if theres anything else I should try first. Thanks!

Cold start video
https://www.youtube.com/watch?v=Pi0ec04nv4s

Light throttle driving video
https://www.youtube.com/watch?v=gQ-FQHe-CwQ

__________________
Garage:
1983 300TD
1985 300D
1993 190E 2.6

Social:
Metric Restoration on Instagram

Is this a turbo OM617 or naturally aspirated?
Phil Forrest

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1972 220D "Trudy," named by a friend.

"The 220D sounds good... I suspect it is the only car that you need a calendar for, rather than a stopwatch, when doing acceleration tests."
Tom Abrahamsson

Did you replace the o-rings along with the crush washers on the delivery valves?

Turbo OM617

On the MW pump there are no o-rings, only crush washers I'm pretty sure. The pump is not leaking.

__________________
Garage:
1983 300TD
1985 300D
1993 190E 2.6

Social:
Metric Restoration on Instagram

How is your vacuum pump? How is your oil pressure?

Phil Forrest

__________________
1972 220D "Trudy," named by a friend.

"The 220D sounds good... I suspect it is the only car that you need a calendar for, rather than a stopwatch, when doing acceleration tests."
Tom Abrahamsson

I just uploaded better videos showing the problem.

Cold start video
https://www.youtube.com/watch?v=Pi0ec04nv4s

Light throttle driving video
https://www.youtube.com/watch?v=gQ-FQHe-CwQ


Oil pressure is great and the vacuum pump is weak, but I have a MB remanufactured one ready to go in next weekend.

__________________
Garage:
1983 300TD
1985 300D
1993 190E 2.6

Social:
Metric Restoration on Instagram

I know the injectors have been rebuilt,I would still look to sticking injectors, poss. poor fuel, pre chamber exit holes partly plugged.
N/A injector pump less fuel is injected, performance would be down.

Listening to your driving video, I cannot hear or see anything out of the ordinary. I also noticed that your engine ran smooth even below normal operating temperature. If it ain't broke, don't fix it, and your video shows nothing out of the ordinary.

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96 E300d

IMO inside a concrete garage most older diesels are gonna sound loud.

I know it's hard to tell through a video. Under light throttle its randomly nailing. Sort of sounds like a ballbearing occasionally rattling around in the engine.

Still, I'd love to figure out the source of the engine rocking/shaking when warm. Feels like a soft miss.

I feel like I've eliminated everything else except the injection pump.

__________________
Garage:
1983 300TD
1985 300D
1993 190E 2.6

Social:
Metric Restoration on Instagram

You mentioned that you put in injectors. Just wondering how many miles you have driven since putting them in?? I have read a number of posts from members who have replaced their injectors who have stated that when first installed, the engine sounded like yours, but usually after driving 100-200 miles, the engine quieted down once the injectors broke in. Some have used additives that sped up the process of breaking the injectors in. Just a thought...........and good luck!!

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96 E300d

Hello buddy


Sent from my iPhone using Tapatalk

I solved the problem. I replaced the delivery valves, springs, and crush washers today and now it runs like a sewing machine. I'm so relived.

Here's the parts in case any one else if having this problem:
Springs
Delivery valves
Crush washers

They're pretty easy to change and only require you to take off the hard lines. The parts above are for an OM617.95X Turbo engine.

I hope my struggle helps someone else out.

__________________
Garage:
1983 300TD
1985 300D
1993 190E 2.6

Social:
Metric Restoration on Instagram

I went through this process and had the same results.
Delivery valves are a fair bit cheaper now…

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1981 240D 4sp manual. Ivory White.

Thank you very much. Our 1980 euro delivery rhd 300TD has had similar problems for years. Motor mounts, dampers, injectors and exhaust hangers have all been replaced and we are now just down to a rough idle, following the motor mount replacement. The delivery valves will be next. We did find one loose injector, not seated properly on the crush washer which was missed by a local diesel mechanic.