Engine shrapnel?

Mike in GA · February 03, 2011, 02:14:34 PM

When an experienced diesel/bus mechanic changed my oil (8v92, MC96a3) he presented me with a 1/4" x 3/8" inch piece of cast metal that apparently came out with the old oil. It is ferrous, and does not seem to be part of a ring, bearing, etc.
The engine's performance has not shown any change recently, does not smoke, or have flat spots. I have had it for 120,000 miles, and it was supposed to have been 'recently rebuilt' some time before I got it. No other debris has come out in the 12 or so prior oil changes- at least none that was apparent.
The mechanic said he wouldn't loose any sleep over it. It may have been left over from a prior rebuild, etc.
One of its four surfaces appears to have been struck or hit – kind of bruised. Not sure if that will show in the photo (haven't added pix to my posts before, so I've got my fingers crossed).
In about 6 weeks the engine is scheduled to be pulled for a transmission swap, and it wouldn't be much work to drop the pan and look for stuff awry.
Any thoughts or suggestions? Oil analysis?
Thanks in advance!
Mike in GA

4905 doc · February 03, 2011, 02:23:31 PM

that looks a lot like one half of a valve keeper. you might want to check the heads and see if one valve is missing one keeper.

papatony · February 03, 2011, 04:29:53 PM

It does look like a valve keeper . I would pull the valve covers and check before i ran it any more. might check the gear on the air comp pump. It won't Take long to check valves and you can guess what happens if one comes loose.

luvrbus · February 03, 2011, 04:44:09 PM

I can't tell the valve keeper locks have the lock on the inside of the keeper look and see if it has ridge on the inside taper they are smooth on the outside

good luck

Brassman · February 03, 2011, 08:14:19 PM

A thorough top-deck inspection seems like a really good idea. Check all those keepers and springs, etc. with a bright light. The look-see is free!

JACKRABBIT4106 · February 03, 2011, 11:04:41 PM

Thought keepers were steel not cast. Could be a piece of a liner?

bevans6 · February 04, 2011, 05:55:15 AM

It's a little common to find bits of engine in the pan after a quickie rebuild or an inframe kind of deal. I've heard of that too many times and experienced it myself. My engine, when I pulled the air box covers to look inside, had a big piece of liner sitting right there. My gearbox, when I drained the oil, had two big bearing rollers in the drain outlet.

Brian

brando4905 · February 04, 2011, 05:58:22 AM

Could this be early signs of gear train failure?

buswarrior · February 04, 2011, 07:31:54 AM

spare parts?

The motto at big transit?

Drive it 'til it breaks.

Costs the same for paid help to open it up, whether broke or not.

happy coaching!
buswarrior

bevans6 · February 04, 2011, 08:47:05 AM

The gears in the 8v71 I am working on look and feel like hardened steel, not machined cast iron. If the grain structure looks like steel, they may be gears, but it it looks like cast iron (homogenous grain structure) they probably aren't gears. I think a lost keeper is a good thought, look for all the valves to have all their keepers. I can't think of a good reason to be taking the keepers out with the head on the engine, but I can think of bad reasons to do that...so it's always a possibility.

Other than that - all sorts of stuff can get left inside an engine...

Brian

luvrbus · February 04, 2011, 08:59:08 AM

Mike do you have Jakes on the engine looks like a piece from a Jake housing

good luck

Van · February 04, 2011, 09:42:51 AM

Oil sample? Maybe?

Mike in GA · February 05, 2011, 05:42:51 AM

Thanks for all the advice guys.
The engine does not have jakes, but an earlier version may have since there is a switch on the dash, "Jacobs Brake". Ironically I am planning on installing a set of jakes when the transmission is swapped this spring.
The piece of metal definitely is cast, not hardened. My first thought was a part of the block at the bottom of the sleeves.
Meantime I have driven from the Lakeland FL area down to Naples - 200 miles or so - ran fine as usual. When I get back up to Lakeland next week I will have John's crew at Central Florida Bus do the valve inspection as suggested.
More as it develops.
Mike in GA

bevans6 · February 05, 2011, 06:21:16 AM

Just look around up top, drop the pan and have a look, look inside the air box through the side covers, and call it done. I really wouldn't worry about it. Big chunks are usually just left-overs, little sandy grains of bronze and grit, and that tell-tale look of gold in the oil is what's bad. "there's bearings in them thar oil!"

Brian