On disassembly
Around 100k got intermittent oil pressure lights.
Soaked and cleaned pickup through drain hole - went away for awhile.
Now at 150K, opened up, new plate gasket, and now into bearings.
Pickup was 6/7s blocked with 'crystal'-y debris, and some (5 sq in) on block near pickup - but not a sludged up motor at all.
All rods down to copper, mains not so bad, except 3 - the thrust bearing - and crank scored.
All seem worn, not foreign deposits/embedded.
I cleaned the journal a tad, back polished another tad, and fitting 1's and 0's mixed to all positions.
Rods smelled horribly of fuel (started project just after an oil change, that was also fuel-y.)
New pump ready to go in; soaked, reamed, and picked pickup clean.

What causes a crystal-y debris?
Will fuel thin oil (but yet not cause overfill) and 'cut' bearings?
Can plate gasket somehow affect oiling or bearings?

 

I don't think anything would cause the oil to crystalize... more likely, something was added to your oil, and THAT is what crystalized down there. Sugar, maybe?

 

How long have you had the truck, or how many miles? You alway inherit former owners habits, good or bad. What oil have been using… brands, conventional or full syn? Change habits? Been using any additives?

 

Had since birth, 150,000 now, religious oil changes, Mobil 1, and 3 or 4 plate gaskets.

Anyone have experience on fuel smell? (Plain old leak, blow-by, plate gasket?)

 

Also, has anyone actually pulled rod bearings themselves?
Mine (99, 5.9, 150K) were down to copper 75-99% showing.
But, I read that in the old days, tri-bearings were very thin 'babbit' / lead / something alloy DESIGNED to give away to the copper, when need be.

So, I'm thinking, maybe my rod bearings did exactly right, gave up babbit to get to copper - AOK, just worn.
My new SP seem to be 'furry' (velvet?) aluminum on steel - so just bi-bearings.

Anyone agree?

 

Measure the crank journals, make sure they are still in spec. Changing rod bearings with the motor still in the vehicle is doable. I've done it several times on various things. However, if your rango is 4x4, it might be easier to pull the motor......

 

Already all rods done, starting to measure mains.
And is 4x4, so doing EVERYTHING right first time!

My one 'cleaned up' journal went to .003 per PG.
Other than that, all in <.002 area, Main 1 at .015.

(I do find stamps in the area of counterweight, but none clearly except "M" with nothing else with it.
I see a piece of a 3, maybe, on the other end, without the M or R adjacent per book.
Anyone know of some samples for font, size, clarity, etc. for these factory stamps?
No bearing indicated anything special.)

7/29 changing fuel injector o-rings (outside), testing for injector leaks, and starting today!

 

Started today!
Had to retard distributor 4 tads (makes up for cam advance) to get idle capable down to 500, but sounds great now.
Gonna' do a couple of heat cycles for leaks, and start driving!
Great oil pressure! Cold so far...

 

Did 5 miles around neighborhood, heated up new paint (!), and the oil held pretty good - cold, warm above 40 mark, hot just below! Keep below 2k RPM so far.