Well, I pulled the PC tonight. It does not have any cracks on the outside. The Ball Pin looks intact, no forign material, or major carbon buildup. It looks like burnt charcoal inside. I noticed what LOOKED like a HAIRline crack on the sidewall below the ball pin level. The tip on the GP side looks like white stoneish pitted and chipped away. The other side is smooth and blackish. Looking down at the piston where the PC was, it was not much to see. VERY black and soot covered, no forign material I could find.

Since I have the glowplug out, I might as well replace it. One less thing to die of old age.

I will post pictures of the PC and homemade tool later tonight when I can get at my digital camera.

This is a view from the bottom looking up.

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This is a side view from the non GP side.

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This is the glowplug side. I am trying my best to get a good "inside" picture.

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Another side view. Notice the little depression twards the mid-lower section. Is this normal? There is another like it on the exact opposide side.

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This is the best ball pin picture I could get. Again, there are no EXTERNAL cracks. Should I consider this one good, put it back in? Or, buy a NEW PC and HOPE replacing it solves the nailing? $120 is quite a lot of money on a lube tech job.

poor picture

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This in in reply to the comment posted by Diesel Power about direct injection engines. If an N14 had three stuck injectors its down for repairs. Because of the many intricate parts that put together the complete valve train of an N14 its not always easy to pinpoint the source of any ticking noises. Yes, it could be a stuck injector, or a worn cam follower pin, or cam lobe or roller, it could be a loose rocker arm, a damaged crosshead, or even a worn wristpin and bushing. Its hard to say without being physically next to this engine. As for the noise coming from your ISB it is more than likely the usual clatter that emits from the VP44 injection pump used on this engine. These particular pumps have a seperate low pressure vane pump in them that supplies up to 300 psi fuel pressure to actuate the various injection timing mechanisms in the pump.

If you ask me anyhting about a Cummins you'll probably get an answer. But the german diesel in my 85 300D is still a learning experience for me. I am currently involved in an entire rebuild of this complicated little engine because of an extremelly loud nailing or knocking that started last month. The engine has about 220,000 miles on it. All this info about the precups is really helping me out. I am rebuilding the head myself to save as much money as possible. Pretty simple since its only a single angle 30* valve job. But after reading these postings I am going to pay extra close attention to those cups. I am still pricing all the parts to build this engine and almost collapsed after finding out the the price of a set of pistons. But I love the car, and I figure its money well spent if it goes another 300,000 after the rebuild. I would definately appreciate any advice with this project. I am not against any suggestions such as removing the EGR system or squeezing more power out of this engine. I would even consider a reasonably sane propane injection system if anyone knows how. If have not heard, propane to a diesel engine is like nitrous to gas.

cumminsnut, you might be amazed to find some "parts" cars out there for $100-$500. If you get even one replacement piston out of the engine, then everything else on the car is almost free.

The person I bought my car from also had an '83 TD parts car for $250 including storage space. I did not take it since I was also new to MB diesels and did not see the need for an old nonrunning car. I'm really kicking myself in the butt for not taking it, but if I see a deal like that again, I'll jump on it for sure!

Looking through FastLane, the precombustion chamber seal rings are offered in 2mm and 2.3mm. I'm inclined to go with the 2.3mm to reduce the risk of protrusion problems. I want to stay low cost but reusing seals, gaskets, bearings, etc. is not the place to get cheap. I know 0.3mm is alot in a precision engine like this, but will it affect anything besides how much the PC sticks into the cylinder?

The only time you would need the thicker precombustion chamber seals is if the head was milled or the bottom of the precombustion chamber bore was machined. Stay with the standard seal. If you put a thicker one in, the tip of the precombustion chamber might have the holes partially obscured. The thicker seals were designed to keep the piston from hitting the tip of the precombustion chamber.

did you fix it??? anyupdates??/

Not even close. I've gotten advice from a few Diesel techs. They keep telling me it's a piston pin. They gave me a 1-2 year lifespan without replacing it. June will be my 2 year mark.

I really don't have any time/money to pull the head and find I also need pistons and sleeves.

just curious , are there any compression leaks(leaking injector, PM, glowplug) in that cylinder??
caz i have same problem with my 89 190D and waiting for the tool to pull PM out.i have it leaking from there.