Volvo Penta AD41P-A Mystery Piece in Oil Pan

[easternmarine]

Alright, just like the title says. I found a small piece of steel (its magnetic) in the oil pan when we dropped it to diagnose why it was locked up. The piece where it was sitting in the pan, seems like it had been sitting there for a while, because there is a black stain in the pain where it was sitting. We have searched everywhere for some type of chip or chunk out of the case, the rods, gears, whatever but can't figure it out. The pistons and sleeves are in perfect shape, so it couldn't have come from the head area. There are a few scratches or gouges in the timing gear cover that MAYBE were caused from this piece passing through. That is speculation. Any ideas? The piece is maybe an inch long, by maybe 1/4-3/8" to about 1/8" thick or so.

 

[Plum]

Alright, just like the title says. I found a small piece of steel (its magnetic) in the oil pan when we dropped it to diagnose why it was locked up. The piece where it was sitting in the pan, seems like it had been sitting there for a while, because there is a black stain in the pain where it was sitting. We have searched everywhere for some type of chip or chunk out of the case, the rods, gears, whatever but can't figure it out. The pistons and sleeves are in perfect shape, so it couldn't have come from the head area. There are a few scratches or gouges in the timing gear cover that MAYBE were caused from this piece passing through. That is speculation. Any ideas? The piece is maybe an inch long, by maybe 1/4-3/8" to about 1/8" thick or so.

The drive adaptor for the raw water pump shaft has a metal insert in it that looks like that

Companion Flange for Volvo Penta Engine Cooling Pump, 858467

 

[easternmarine]

ALRIGHTY, now I think we are getting somewhere, because that piece is there AND it has the metal insert, but its definitely doesn't look as old as the engine AND it certainly is in that cover area where if it came free it would have gouged the cover!!! I think you are EXACTLY right! This makes me feel better that its not something we won't find. Do you think the scratches in that cover are just fine left as is? I assume it doesn't matter?

 

[Plum]

ALRIGHTY, now I think we are getting somewhere, because that piece is there AND it has the metal insert, but its definitely doesn't look as old as the engine AND it certainly is in that cover area where if it came free it would have gouged the cover!!! I think you are EXACTLY right! This makes me feel better that its not something we won't find. Do you think the scratches in that cover are just fine left as is? I assume it doesn't matter?

Good news. So I guess that drive adaptor broke sometime previously but wonder what overloaded it? . I would not worry about the scratches, as long as the gear train and oil pump drive and associated bearings are all good. You mentioned "locked up", if that part in the sump was not the cause as it had been replaced already, what locked up?

 

[easternmarine]

Thanks again. Well we took it all apart because the crank would not turn all the way over. We discovered a bent rod, but everything else looked great. There is definitely signs of corrosion, not a lot, but certainly some patches of surface rust here and there. The intercooler chamber also has corrosion in it. I'm thinking the intercooler itself might have a leak, although I filled it up with water and let it sit overnight and nothing leaked out, but its bulged at the bottom where the drain plug is and the case itself has a hair line crack where the bulge is like it froze.

 

[Plum]

Thanks again. Well we took it all apart because the crank would not turn all the way over. We discovered a bent rod, but everything else looked great. There is definitely signs of corrosion, not a lot, but certainly some patches of surface rust here and there. The intercooler chamber also has corrosion in it. I'm thinking the intercooler itself might have a leak, although I filled it up with water and let it sit overnight and nothing leaked out, but its bulged at the bottom where the drain plug is and the case itself has a hair line crack where the bulge is like it froze.

Inner core does not look pretty. At the very least I would air pressure test it to 20psi in a water trough for 10 minutes. The outer housing only has to withstand boost pressure and the engine will not stop if those craks get worse

 

[easternmarine]

How would you pressure test it? The top is just a big open rectangle?

 

[Plum]

How would you pressure test it? The top is just a big open rectangle?

Put it in the housing so you can clamp on the lid that has the two water spiggots to use. One blanked, the other to the tester. Or, not tried this, clamp a sheet of thick perspex to the top with a sheet of neoprene as a gasket and pressure test through the drain plug?

 

[easternmarine]

Thanks, I think I had already started to work on putting it back in the case. That drain plug seems in there really good. Only problem is that I can't really see it in the case, but I guess that doesn't matter. I may still try the sheet with neoprene. Thank you for the suggestion.

 

[snowbird30ds]

If that piece has dropped down around the gears have them properly crack tested while it's apart (search for local ndt places) in case of a tooth letting go later on.