I offer this not to be a smart A. and not to rob the thread.
I also recognise that a dealer won't want to fiddle nor let you have access to do this in their shop.
I haven't had this issue with this motor but I did pre-think for when I changed my GP's. I have used similar techniques for other motors offering even less access. Actually it was many years ago and a borescope was not to be had - it was a remote rural setting so a desperate stab in the dark worked out fine saving thousands of dollars.

Firstly - I thought pulling the injector as was suggested earlier in the thread was entirely logical - as you would know which one to pull from knowing which GP fragged.
A borescope with F2.8 would permit viewing of most of the bore and if the piston were too high for the following technique you would still be able to drop it through its stroke - just not any up stroke unless you have seen the fragment sitting rather centrally on the piston crown. You would at least know what you were looking for from the broken part. I assume they have presented you with YOURS.
If it is central - a piece of thin plastic tubing of the type used in larger pump / sprayer packs could have some old-fashioned plasticine stuffed well into the end so you don't get it all over the injector inlet and the crown of the piston.
I have also created a fairly controllable vacuum by passing compressed air across the top of the tube (using the old Bernoulli effect) to create sufficient negative pressure at the tube tip to pick up fragments.
I have also created (using the blue-tack/plasticine thing) a type of manouverable endoscopic pick-up using two lengths of nichrome wire pushed into the tube - to go left pull one - to go right pull or push the other. It is limited but can flex quite controllably. To move the tube in and out make sure it is straight and carefully project/withdraw in order not to scrape off plastic shards this creating a further problem.

If you can work with the borescope in the GP hole you may be able to see what you are doing if the piston is in the right place. As I said I haven't tried it in this motor but I can't see why it would not be worth trying rather than taking the head off.
On it being magnetic, I would be imagining ferric content would be extremely low and it would be more tungsten based.
As all of the holes we are talking about are in the order of 10 mm diameter - a quality borescope will handle that and you should be able to write/send the image to the screen or even print it from an SD card.

Please don't laugh to hard at me for this. It has been fluked before. Good luck.

I just broke one of my old ones. I was Wrong. NO Metal. So a magnet will not work.

_________________
05 Liberty CRD Sport with Leather 115k
GDE ECO, No EGR, no FCV, (system gone)
Oil Drain plug P/N 090-039
K&N Air Filter, 2nd gen Fuel filter head
NEW Rockers & lifters
Mobil 1 0w-40
Stant 13519 195 deg inline Thermostat.
0 281 002 845 MAP
Etecno GX3123 7v Glow Plugs
Advance Gold 800CCA Battery
Traded it for a Quality VW TDI

talking to a few better diesel mechanics than me,

They say that with ceramic glow plugs, whenever possible, pull injectors, install a pressure tester, rotate to close valves for that cylinder, THEN remove the glow plug with the tester pressurized. This will push any fragments out.

The flip side to that coin is that you should put a rag over the hole as you're pulling it out, to keep the parts from shooting halfway across the shop. Wear good gloves, and safety shield or glasses....it will come out at whatever pressure the compressor regulator is set to.

Update Jeep towed to different shop Glow plugs changed out Head removal not required as GP had old break and passed piece ( wthout any damage to motor) Now awating new ecu ( on backorder) What a nitemare this has been!!







)

Why a new ECU? What's wrong with yours? Hope that's not the Dealer drawing straws again?

That's got to be expensive?

KJJET

_________________
05 Liberty CRD Sport with Leather 115k
GDE ECO, No EGR, no FCV, (system gone)
Oil Drain plug P/N 090-039
K&N Air Filter, 2nd gen Fuel filter head
NEW Rockers & lifters
Mobil 1 0w-40
Stant 13519 195 deg inline Thermostat.
0 281 002 845 MAP
Etecno GX3123 7v Glow Plugs
Advance Gold 800CCA Battery
Traded it for a Quality VW TDI

our new shop needed to return crd to local dealership for a newflash on ecu after new GP's and new turbo boost sensor were installed as codes and sel lite would not clear (unless old ecu was grounded ) old ecu was flashed by dealership but crd now would no longer start new replacement ecu installed ( codes and sel will still not clear ) new ecu now on backorder. Yes it is costly quoted 1grand plus. reading all this maybe it would be better to have a d9 cat run over the crd (however my wife loves it as she has used it offroad for she job and it has not embarassed her ) if the new ecu fails to clear codes and sel i may buy a d9 cat lol

OMG... I'm not a betting man but I would place all the cash in my pocket that its not the ECM. You Need to Contact Keith at Green Diesel Engineering. He can flash your ECM and most likely test it! probably for under $100.

Good luck
KJJET

_________________
05 Liberty CRD Sport with Leather 115k
GDE ECO, No EGR, no FCV, (system gone)
Oil Drain plug P/N 090-039
K&N Air Filter, 2nd gen Fuel filter head
NEW Rockers & lifters
Mobil 1 0w-40
Stant 13519 195 deg inline Thermostat.
0 281 002 845 MAP
Etecno GX3123 7v Glow Plugs
Advance Gold 800CCA Battery
Traded it for a Quality VW TDI