Ford 3550 knocking?

[Moparminnion]

Hello all! Long time lurker finally decided to join because looks like my backhoe project isn't going to be as simple as I'd wished.
Everytime I Google something ,this forum pops up so here I am lol.

So I've come into a left for dead 3550 industrial backhoe .
I picked it up with no history from a buddy that runs a scrap yard other than it turns over but won't start .
So I load it up and bring it home .
They burnt up the starter trying to start it, so I had that rebuilt .
Cables were missing so I made new ones from aught gauge welding lead.
All fuel lines removed ,cleaned, reinstalled, as well as a new fuel filter .
IP wasn't putting out fuel so I had it and the injectors rebuilt by the most reputable diesel shop in my area.
1700 later .
Now she runs ,but this little dude is loud !
Like I think it's knocking loud !
I had my stepson look at it ( he's a certified Kubota technician)
And he kind thinks it might be knocking too.
But not enough to be sure since this yellow contraption isn't orange, lol.
Is there anyway I can besure besides dropping the pan and seeing how much the big ends shake ?

I don't mind spending money to solve a problem, but I can't stand spending money when I don't need to.

Edit : new to the site and didn't know I should have posted here originally.

Going to cut open oil filter later and see what I can see

 

[Fordfarmer]

Do you have a GOOD muffler on it? Those 3
cylinder diesels are loud.
I won't say it isn't the bottom end, but
unless it's been neglected, they tend to
last a LONG time. 4 mains on a 3 cylinder,
wide, large diameter mains and rods, and a
good oiling system. My 4600's main and
rod bearings were still within spec at
8500 hours, when I rebuilt it due to
cylinder wall cavitation.

 

[Moparminnion]

That's what I keep seeing is how dynamite these little motors are .
Couldn't tell you much about the muffler except it looks solid .
A noisy motor dosent bother me ,but I am scared of it being a problem and not addressing it and punching a hole in an otherwise rebuildable block.

 

[Bern]

Typically if you have a rod bearing or wrist pin bushing going out, the knock will get progressively louder as you rev it up.
The harder the piston smacks the valve or cylinder head, the more noise it makes.

If it were mine I'd pull the injectors out and send a borescope down the holes to look at the tops of the pistons. If all you
see is a coating of light black, it's likely not a bottom end problem. If you end up going the borescope route, make sure that
the pistons are not at TDC because all you'll be looking at is the piston crater, which will not show evidence of any impacts.

As Fordfarmer said, those 3-cylinder engines are naturally loud, even more so if the timing is too far advanced. You could try
temporarily retarding the timing and see if it goes away. Easy to do with the CAV pump.

 

[Moparminnion]

So I did set pump timing at 1/2 a mark before 0 like I read on another post here.
The engine as a whole gets louder with rpm ,but the knock seems to stay consistent with the engine volume .
And I think that's what stumps me.

It's not the knock getting louder just the whole engine.
But it does seem to have a miss , but I was thinking that's due to the uneven number of cylinders.

I'm omw over to cut the filter open and maybe do the injector test .
I'll report back with findings

 

[Bern]

Try retarding the pump timing, it'll take you maybe 5-10 minutes. Just loosen the 3 bolts and rotate the top of the pump
towards the center of the engine.

 

[ErnieD]

change oil, cut open open filter, look for flakes

send oil to lab for metals analysis

 

[ptfarmer]

Put a good oil pressure guage on it, that will help alot.

 

[root]

I have a 69 4000 3cly diesel and a 98 4630 with essentially the same 3cly diesel. Both are loud but my 69 rattles a lot more. There are more webs cast into the outside of the block on the 98 that are supposed to quiet it down some. I rebuilt the 69 because it was tired and had a lot of blow by. It's still just as loud after the rebuild.

 

[Moparminnion]

So update on the backhoe.
Cut the filter open and found 0 flakes of anything .
Showed my engine rebuilder and he said it was a good looking filter ,so i spun a new filter on and have been running the engine here and there as i make more and more repairs to it ,getting it ready for service .
Just ordered new tires and putting them on.

 

[Old Ford Mechanic]

Might pull the cover and check valve lash if not done so already.

 

[Moparminnion]

Thats probably a smart idea .
Ill try that!