Strange IDIT lubrication failure...

[Thewespaul]

tearing down an engine I got as a core exchange, running engine that was pulled with the passenger side of the engine full of metal shavings. I got this engine a year or so ago but just pulled it apart for the rods today.

Found some very odd things that I’d like to hear some thought on before I weigh in. The side that was full of shavings I found some of the most severe rocker wear I’ve seen on an idi. But oddly, it’s only on one valve per each rocker pair, one side will look normal and the other has a circular gouge worn almost all the way though:

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Drivers side looked absolutely normal. This engine has less than 100k on it as well.

On the bottom end nothing was out of place except for one rod bearing that speaks for itself, every other bearing looked like new.

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What do y’all think?

 

[laserjock]

Pushrods through the rocker has happened I believe. @pafixitman

 

[Thewespaul]

Pushrods through the rocker has happened I believe. @pafixitman

Push rod side is fine, the wear is where the rocker rides on the valve stem.

 

[laserjock]

That side is oiled by a hole in the top of the rocker as it dribbles down from the pushrods end right?

 

[Thewespaul]

Yep, pretty much just an oil bath

 

[laserjock]

Since nobody else has weighed in...

So bad rod bearing starved that side? I can’t find my oil passage diagram but oil travels from driver side to pass side. Oil goes up from the crank mains to the cam bearings and then the piston squirters, lifters, pushrods, then rockers. So I suppose the bad bearing could cause the starvation up top. The pattern is a bit of a mystery but it might make sense if I had the oil path in front of me.

 

[Thewespaul]

I believe you’re spot on mike, passenger side gets oil last iirc.

My best guess is this engine got ran out of oil, possibly an oil feed failure (sound familiar?) and it wiped out the valve train on the passenger side. I bet oil got finally added once the rod started knocking, but it’s still very odd to me that a rod would loose lubrication before the drivers side valvetrain, but possibly the bearing faliure was heat related from the engine overheating, causing the tolerances to tighten up and make that bearing want to spin?

I definitly don’t have a sure answer at all, I’m curious to see what @IDIBRONCO thinks.

 

[IDIBRONCO]

I'm at a loss here. This is only the second or third spun bearing that I've seen in one of our engines. It just almost never happens. 6.2/6.5 Chevys on the other hand, well that's not all that uncommon with them. Assuming that the extreme wear is on the exhaust valve side, then here's my shot in the dark/way out there guess. I'm going to go with poor (or none) maintenance. Since the passenger's side was full of metal shavings, I'm going to guess that something like sludge or a piece of crud partially blocked the oiling hole to the spun bearing. This caused metal shavings to get pushed into the passenger's side oil gallies, starving, but not eliminating the oil feed to this side. Next, I'm guessing that the reduction in oil feed may have caused this head to run hotter than the other side. Then, since they run hotter anyway, the exhaust valves got a little bit sticky, causing the rockers to have to push harder to open them, increasing heat and friction (again due to reduced oil flow). That's my fictional story of what happened. Maybe it's all or partly true, maybe not.

 

[79jasper]

So, hows the serial number location look? Rebuilder stamp?

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[Thewespaul]

So, hows the serial number location look? Rebuilder stamp?

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It had never been apart, 98k miles on it before getting pulled.

 

[Thewespaul]

I'm at a loss here. This is only the second or third spun bearing that I've seen in one of our engines. It just almost never happens. 6.2/6.5 Chevys on the other hand, well that's not all that uncommon with them. Assuming that the extreme wear is on the exhaust valve side, then here's my shot in the dark/way out there guess. I'm going to go with poor (or none) maintenance. Since the passenger's side was full of metal shavings, I'm going to guess that something like sludge or a piece of crud partially blocked the oiling hole to the spun bearing. This caused metal shavings to get pushed into the passenger's side oil gallies, starving, but not eliminating the oil feed to this side. Next, I'm guessing that the reduction in oil feed may have caused this head to run hotter than the other side. Then, since they run hotter anyway, the exhaust valves got a little bit sticky, causing the rockers to have to push harder to open them, increasing heat and friction (again due to reduced oil flow). That's my fictional story of what happened. Maybe it's all or partly true, maybe not.

I could definitely see that, and likewise Ive never seen a spun bearing on an 7.3 or 6.9, only rod faliures. This engine was a lot firsts for me, Id say at least four of the lifters had blown apart and were hollow.

 

[Frstdiesel]

Since it is relatively a low mile engine, I would tend to agree with idibronco's.
Poor or no maintenance, probably sludged up?
For what it's worth, when I tore down my '84 6.9 with 90k on it, I found lots of clear silicone stopping up several tubes in the oil cooler, red silicone stuck in the water passages, etc.

 

[79jasper]

It had never been apart, 98k miles on it before getting pulled.

Interesting. Was just a thought. Lol

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[typ4]

3rd cyl back pass side spun?

Also lots of idling time will eat rockers because the tips are splash lube only, neds rpm to create the mist.

 

[Thewespaul]

I can’t recall which hole it was that spun the bearing, but it’s was pretty sluggy inside. But most IDIs I get as cores are