Well, I wasn't able to make any progress for a few days, but I got back to it today. I put the freshly cleaned, pop tested, and balanced injectors in, and started it up. Still knocking like crazy.
Next I drained all the oil into a really clean pan, and then strained the oil through a fine wire-mesh screened funnel. Close examination of the the stuff strained out of the oil didn't tell me much. There was a little dirt and debris, and just a few little flakes of metal - nothing like what I'd expect from a wasted rod bearing.

Lastly I pumped all the fuel I could out of the tank, put 7 gallons of fresh diesel in it and reconnected every thing. Started 'er up and let it idle a few minutes. No change. It is still knocking like it is about to fly apart. Here is a link to a short video clip (with sound) I took today. At this point I'm thinking the engine is toast. You guys have a listen and let me know what you think...

__________________
1984 300 Coupe TurboDiesel
Silver blue paint over navy blue interior
2nd owner & 2nd engine in an otherwise
99% original unmolested car
~210k miles on the clock

1986 Ford F250 4x4 Supercab
Charcoal & blue two tone paint over burgundy interior
Banks turbo, DRW, ZF-5 & SMF conversion
152k on the clock - actual mileage unknown

It's not good and it sounds like a severe injector knock.

See if you can isolate it to one cylinder. Crack each injector line, one at a time, while it's at idle. See if the noise disappears with one of the five.

Report back.

I did that before I pulled the injectors and had them cleaned, pop tested, and balanced. Wonder if it could be the pump not putting out the way it should on one (or more) cylinders? If you recall, this all started when I pumped 5 gallons of suspected bad/mixed fuel into an empty tank.

I'll try cracking injector lines one at a time again...

__________________
1984 300 Coupe TurboDiesel
Silver blue paint over navy blue interior
2nd owner & 2nd engine in an otherwise
99% original unmolested car
~210k miles on the clock

1986 Ford F250 4x4 Supercab
Charcoal & blue two tone paint over burgundy interior
Banks turbo, DRW, ZF-5 & SMF conversion
152k on the clock - actual mileage unknown

I am certainly no expert. The rap to me does not sound sharp enough to be a rod bearing. Could be the audio reproduction or my limited experience of course. Still since you have kind of tied it down to #2 cylinder the rod bearing is inspectable through the lower oil pan.

I originally suspected some sort of piston damage. The compression test alone is not conclusive it is not there. Blowby is not noticeably greater is it? I also do not think it is being caused by your injection pump . Pump damage from the wrong fuel could damage the pump of course. This form of noise normally would not be the result if so in my opinion. This comment is only based on my also limited knowledge of pump function.

The running stress on gasoline might be enough to break an engine crankshaft even. A broken crank sometimes is evident when you shut down the engine it makes a clang.

Also a quick check of the front balancer for being loose would not hurt. I have seen changing dynamics in engine operation loosen them up on certain cars. If you were burning gasoline you can honestly say the dynamics where different.

Perhaps it's time to fixate on writing two registered letters. One to the station owner and one to the shell oil company. With a little luck on your side they can have the joy of dealing with the overall problem.

Shell oil made several billion dollars profit last year. A piddling engine repair should not put them out of business. At least their not standing in line for a bailout. I would like one as well. Just not rich enough to get one I guess.

You also had to stop burning vegatable oil. Had you continued and not gone back to diesel fossil fuel this problem would not be there. We finally have a potential case of vegatable oil burning being superior to diesel for engine longevity. I never would have suspected......

The blowby doesn't seem to have increased significantly. What kind of piston damage could cause that kind of knock - wrist pin maybe?

Never noticed the "clang" you mentioned at shut down (indicative of a broken crank).

I've reported the problem to the local weights and measures office. We'll see what they can uncover....

__________________
1984 300 Coupe TurboDiesel
Silver blue paint over navy blue interior
2nd owner & 2nd engine in an otherwise
99% original unmolested car
~210k miles on the clock

1986 Ford F250 4x4 Supercab
Charcoal & blue two tone paint over burgundy interior
Banks turbo, DRW, ZF-5 & SMF conversion
152k on the clock - actual mileage unknown

I don't believe it's a wrist pin or a bearing of any type. It has a softer sound to it as though it's a combustion knock. So, it could be anything from a damaged prechamber to a damaged piston........anything that disturbs the normal combustion within the cylinder.

You need to see if you can find the affected cylinder and pull the prechamber on that cylinder and start looking around.

Any idea where a guy could get his hands on the tool to pull out the prechamber(s) - and any tips/tricks on doing the job? Is there anything more to it than just getting the right tool and unscrewing it out of the head?

What kind of piston damage could possibly cause a knock like that? I'm going to get a better audio clip and post it tomorrow.

__________________
1984 300 Coupe TurboDiesel
Silver blue paint over navy blue interior
2nd owner & 2nd engine in an otherwise
99% original unmolested car
~210k miles on the clock

1986 Ford F250 4x4 Supercab
Charcoal & blue two tone paint over burgundy interior
Banks turbo, DRW, ZF-5 & SMF conversion
152k on the clock - actual mileage unknown

The tool is a slide hammer...........it uses impact to dislodge the prechamber from the head. No, there are no tricks..........just patience.

So, what, you just thread it into the prechamber in place of the injector and work the slide-hammer until it pops out? It looks like there are a couple of slots for "tangs" to fit into - like it is threaded in...

__________________
1984 300 Coupe TurboDiesel
Silver blue paint over navy blue interior
2nd owner & 2nd engine in an otherwise
99% original unmolested car
~210k miles on the clock

1986 Ford F250 4x4 Supercab
Charcoal & blue two tone paint over burgundy interior
Banks turbo, DRW, ZF-5 & SMF conversion
152k on the clock - actual mileage unknown

It does thread into the prechamber and the slide hammer develops the force to remove it.

The locking ring is removed first, of course.

I wish I knew more about the effects of burning gas in a diesel engine. As I earlier stated some engines seem to tollerate it better than others.
When we take an older engine with lots of miles and subject it to serious new stresses perhaps things that were good at the lower stress levels just cannot take it.

The only assumptions besides the hotter combustion is the ignition point of the gasoline is earlier. This hammering preignition effect can be disastorious. At least the gasoline burns slower than the diesel I believe once ignited. Yet in a high compression situation like a diesel engine the shock waves from burning gasoline must be substantial.

As for gettting satisfaction for things that go wrong in life. My first rule is the higher the individuals activity level the more events you attract and have to deal with. I am far too active for my age so I usually get a few each year.Plus of course the few still outstanding from the previous years.

My rate of succesful resolutions is not as good as I would like. That forces me to try to keep everything in perpective. I think you have a fighting chance with shell. Unless corporate policy is totally head in the sand. Unlikely in my opinion.

Depends on who you reach perhaps as well. Always ask for their superiors name when they say no. Find the insurance companies name for the service station for example. This all is a way to apply pressure.

Small claims court or the threat of it can move things along. Sometimes they just hate loosing control of a situation. You cannot win them all yet one has to try or they win. Hope your states regulatory agencies can help.

OK, so I need to remove the locking ring first (the part with the "tang" slots) THEN use a slide hammer to remove the prechamber? How does the slide-hammer "attach" to the prechamber?

Anybody know where I can get the appropriate tools? Or better yet, info on how to make them?

__________________
1984 300 Coupe TurboDiesel
Silver blue paint over navy blue interior
2nd owner & 2nd engine in an otherwise
99% original unmolested car
~210k miles on the clock

1986 Ford F250 4x4 Supercab
Charcoal & blue two tone paint over burgundy interior
Banks turbo, DRW, ZF-5 & SMF conversion
152k on the clock - actual mileage unknown

I know you can use a bicycle crank as a puller. Just thread it into the prechamber and go at it with a slide hammer. It should not be too hard to make something to pull the lock ring.

Could running a gas mix have broken some rings?

__________________
1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

1982 300SD - 232K miles - Wife's Daily Driver

1986 560SL - Wife's red speed machine

In the archives you will find some people use a part of a bicycle pedal assembly to remove the prechambers. The use description is incorporated as well. Apparently the thread pattern is the same.

The factory type tool also might be in the tool rental program on site.

You mentioned earlier in the thread you thought that the oil pressure seemed low. Has it come up since clearing up the gas/diesel issue? Oil pressure is developed through the bearings, and if yours are shot, then your pressure will go away, further exasperating the issue. But if the pressure is back, then I'd say continue looking.

mjk
84 300SD - 90.3 Kmi
84 300D - 326Kmi when oil left engine