What the H*** is this Little Piece of Iron?

[bobk]

Cleaned and remoted the air box drain check valves today (6V92TA) per the advice from Karl and others on the forum and found a small piece of iron in the outboard port check valve. It seems to have a slight curve to it. Pictures attached.

The engine is running well, no smoke, starts easily as it should in S Florida. Minimal oil consumption so long as it is below the full mark. Is this what I'm afraid it is? Engines were rebuilt by the PO about 600 hours ago and just made a 1700 mile trip without incident.

Could this have been left in the airbox during the rebuild and worked it's way out after the fact? What should I do before I start north?

Bob
48MY series I

 

[Genesis]

Weeeelllll, I know what it looks like!

I suspect you do too.

Let's hope it either isn't, or it was left in there (which is damn sloppy, as that could have been aspirated into a port with catastrophic results) In fact, there's a decent chance that what you're looking at is a situation where the check valves were not removed or replaced when the "overhaul" was done by the PO, and that was part of WHY they were overhauled! That's even sloppier but I wouldn't be shocked if this is yet another example of doing half the job on a so-called "major".

I wouldn't tear anything apart if everything is running ok. If it is what it appears to be and came out of one of the currently installed jugs then there's not a thing you can do about it and the problem will be confined to that hole anyway. If that's the case then you're going to be doing a hole - no way around it. But if not you're going to do a lot of work and/or go to a lot of expense for nothing!

Unfortunately there is no GOOD way to look on the V series engines. To get access to both sides of the ports you need to pull the blower, aftercooler and both exhaust manifolds so you can remove the airbox covers and get clear access to inspect, and even then there's no guarantee you'll see it (just depends on how things line up.)

So I say if the engine is running good run the boat. You got two engines; if one goes down you have one remaining to get you wherever you need to go, albiet at a much slower speed.

 

[luckydave215]

Karl, if there's that big a piece of compresison ring in the airbox, and it came out of the current set of parts, ( ) the hole is certainly wounded.
The death parts wouldn't have to be lined up anywhere particular, and you would be able to see the gouges in the bore from the "outside" ports. I'd expect to see the exhaust port(s) beaten up pretty badly.
The damage will be as obvious as a cow in church.
That being said, I'm also of the opinion this "mystery part" is evidence of a sloppy previous rebuild.

 

[Trojan]

From the picture, it looks it may have been in there a long time. Lets hope it's from an old rebuild. With a Piece that big I would think you would show a little smoke. It looks like a chunk of compression ring. A compression check may show if there is a broken compression ring. But if everything running OK I would not worry. If it ain't broke------------.

BILL

 

[captddis]

Is this the 48 that had the soot ingestion? If so this is just the beginning. Hate to be a doom and gloom guy, but seen it too many times. Usually 200hr after the soot event. If you pull the turbos you will probably find some damage as well. They will run for years with broken rings, just be smokey and often there will not be any more oil consumption than normal.

 

[Genesis]

Karl, if there's that big a piece of compresison ring in the airbox, and it came out of the current set of parts, ( ) the hole is certainly wounded.
The death parts wouldn't have to be lined up anywhere particular, and you would be able to see the gouges in the bore from the "outside" ports. I'd expect to see the exhaust port(s) beaten up pretty badly.
The damage will be as obvious as a cow in church.
That being said, I'm also of the opinion this "mystery part" is evidence of a sloppy previous rebuild.

Well yeah, if its off the CURRENT parts then the involved hole is toast - it is a matter of when, not if.

You won't be able to see the gouge without getting in there to look. And you can't get in there to look on any sort of comprehensive basis on the V92 engines without pulling the aftercooler for the "in the V" access, and the exhaust manifolds for the outside access (you can't even get the airbox covers OFF on many of these engines with the manifolds on the motor!)

That's a hell of a lot of work for something that you can't do a thing about without tearing the motor apart.

I say run it. If it starts smoking then shut it down - you have your answer - and run on the remaining one to get where you need to go.

If I was the guy who did the rebuild I'd KNOW it was trouble because I'd have cleaned the airboxes and changed the check valves. But the current owner doesn't know how good of a job the PO did on the overhaul, and it was 600 hours ago. So there may or may not be a CURRENT problem, and I'm just not comfortable with ripping an engine apart without hard evidence that there's a reason to do it.

If you wanted to get aggressive on the diags you're going to have to pull the blower, aftercooler, and manifolds to get enough access to have a DETAILED look at the cylinder condition through the ports. A CAREFUL inspection via that should tell you what's what. But that's a LOT of work (easily a man-day to pull it apart and another full one to put it back together)...... we're talking about a couple of grand if you pay to have someone do it......

 

[bobk]

Thanks for all the feedback/advice. It looks like a followup post I made late last night got lost, so I'll put some additional pieces together here.

First, as captdis remembered, this is the 48 that had a brief soot ingestion before I bought it. The leak was inboard starboard. The piece of ring was outboard port. And there has been no further soot deposit in the ER.

The intake sides of the turbo blades were clean enough that no service was needed at the time we bought her or 20 hours later on the fall oil change or the most recent change after another 180 hours.

The aftercoolers were pulled for cleaning last fall, 400+ hours after rebuilds, and we found little blockage. I've got CRS on this, but think it was 10% blocked. The mech who did the work is one of Baltimore's most respected DD mechanics. He's ex J&T with at least 20 years on DD's. He saw nothing wrong in what he could inspect and also did a tune up at that time. I'll call him later to confirm his observations.

But this all seems to add up to an old issue? We are not seeing smoke, just the normal brief puff on start-up and a brief puff when we bring the RPM up following long cruise at 1100 RPM..

So it sounds like the concensus is leave well enough alone and and start our trip. Is there anything else that is simple that I can do to add piece of mind?

Bob

 

[luckydave215]

And you can't get in there to look on any sort of comprehensive basis on the V92 engines without pulling the aftercooler for the "in the V" access, and the exhaust manifolds for the outside access (you can't even get the airbox covers OFF on many of these engines with the manifolds on the motor!)

Doh! I only know about 71 series access to the airbox covers............it was easy on mine.

 

[bobk]

I spoke with my mech yesterday and he confirms that the area of the pistons, rings and cross hatch that he could see were all normal last fall when he cleaned the aftercoolers. He tells me that even a small piece of ring missing would make the rest of the ring turn black.

Also he says that it would smoke at startup if there is a bad ring. I double checked it and the puff of light blue/grey smoke cleared in just a couple of seconds just like the other side.

So, I guess we are good to go.

Thanks again for the help/advice.

Bob
48MY Series I