it may have gone down the bore. or one of the liners is religeos and it has gone into the water jacket.

either way the engine probably needs a rebuild of some description it may only be a decoke and lap the valves fit new liners rings and bearings and a full gasket/seal kit. the problem is no way to tell until you dismantle and measure everything.

I’m getting ahead of myself but where’s the best place to purchase the parts you listed. Do you happen to know how costly these items are?

I removed the exhaust and air intake manifolds today and cleaned out the exhaust ports (in the block) by hand. With the aid of a flashlight I could see debris further back in the exhaust port openings that were not accessible by hand. There was a little bit of rust in one of the openings. The air intake openings were clean. I think the mystery of where the excess lubricant went to has been solved: it was in the intake air manifold.

Questions - where  does the exhaust port opening lead to? A valve? In one of the discussions the member was interested in using a boroscope going through the “ pre combustion chamber “ to inspect the cylinder with. Where is the pre combustion chamber? Is there a diagram somewhere showing the cross section of the head and block?

For the next steps I’m thinking about spraying diesel fuel under pressure in the exhaust port openings and then suctioning out the fluid to try and clean out the remaining debris. I also plan to remove the side panels to inspect and lubricate the lower parts if possible. The inevitable I suspect is to remove the heads. When that time comes I will need your guidance for sure.

Thanks everyone for your input.

the easiest way to clean any debris from the cyl is remove the heads while their off get them crack tested (magna-fluxed or dye-check (magna-flux for ferrous parts, dye check for non ferrous it can also do ferrous parts too) and relap(hand grind with valve paste) the valves, replace valve stem seals, check mating surfaces for trueness etc
yes the exhuast port leads to a valve.

the pre comps are part of the head assembly the injector sprays into the pre comp and the flame front propagates from there to the cyl its part of the reason older diesels have that distinctive sound. new engines are direct injection. its all to do with mixing the fuel with the air. usually on the intake side of engine.

for parts try your nearest cat dealer it helps if you have a parts book they can use the older part no to find the correct part.
if its common and still used today its cheap if its not common its more exspensive.

proper ball/ roller bearings and oil seals can be obtained from bearing shops if you can read the code numbers off the part or they can match by measurement always take the old part with you to compare.

try google searches too i have found interchange part numbers that way.

BEFORE you do anything get a copy of the serviceman's reference for your machine note there is a separate one for the engine and hydraulics(if fitted) in some older machines, a operators & maintenance book and the parts books for the machine and any attachments such as hydraulic control and blade.

these books are very usefull before attempting any job.
their is also the acmoc members tech libray (you must be a financial member of acmoc its well worth the annual club fee)

Does anyone know the approximate weight of the heads on a 17A?

Bare head is 120 lbs each.

I have a question - in order to manually turn the crank from the front of the engine you would need to turn the nut on the crankshaft pulley. Is that right? I’ve instead seen references to prying a certain gear tooth and no mention of the crank pulley. The reason I’m asking is that the approach I’ve taken is to use a pinion gear to turn the flywheel. The problem is that because the pinion gear has a clutch I’m limited to moving the flywheel in one direction. I’d like to be able to move the flywheel backwards as well as forward. I might have a better chance at dislodging an obstruction if one exists at all. My 17A has a hydraulic blade lift. To get at the crank pulley I assume that the radiator and the hydraulic fluid tank would have to be removed. Is that right?

The other option is to remove the timing point cover and indicator at the top of the flywheel housing. You can then get a pry bar in there to access the ring gear teeth and pry back and forth.

That’s a great idea Old Magnet and I will give it a go within the next few days. However I’m wondering if I could “lock” the pinion gear clutch somehow. I’ll ask the fellow who rebuilt the starter for me.