Oil samples showing high metals after 65Hrs. Whaty happened??

[Shaunc]

I had my oil sampled back in March 22 and got a clean bill of health and it was recommended that I was good for another 80-100 hrs. So i went on a long trip.

This was the feed back in March

Well, hotdog! If this oil was really run 350 hours, these results are fantastic, especially since it seems you're no longer fielding a problem with the fuel system. Wear metals look great both in relation to past reports and universal averages. Silicon is elevated and could be dirt, but since wear looks so good, we doubt it - maybe it's a harmless sealer or lube used during recent work? The viscosity is a hair thin, but in the absence of fuel, it's not a problem. No other contamination was found. Nice! We'll hope the port side report looks a lot like this one.

65 hrs later I changed the oil and sent in samples.

I was horrified to get this report back. No work was done. Anyone with input would be awesome.

My mechanic and the labs suggested a 20 hr run on the new oil and then do new samples and check again

Metals are quite a bit higher than they were back in March. Iron, copper, and lead are all much higher, possibly indicating wear at a steel/bronze interface, such as bushings or bearings. It's been just 65 hours since the previous sample, and whether that oil has been changed or not, this is a steep increase over such a short time. If any engine work was done, especially with new parts being installed, that might explain it. Silicon could be from sealers or gaskets, but it might also show abrasive dirt, causing wear. If there's no recent work to explain this, use caution.

[Captain Ralph]

Who is doing the lab work?

[Shaunc]

Blackstone and have done this for 6 yrs

[Pascal]

How long have you had the boat? Is it possible that the first sample was much fresher oil than 350 hours? That s a lot of hours between oil change… if you recently bought the boat maybe the seller had done a recent oil change but claimed higher hours to cover the results of the sample. Don’t ask how I know it happens.

[Captain Ralph]

What engines, tune and clutches?
Same report on both engines?

Is it 20 hours yet?

[Shaunc]

I have had the boat 7 years and done quite a few oil samples and oil changes on my 8v71’s. Alison transmissionsThe oil was sampled before going to 350hrs and all was good to keep going with out changing. This is my SB motor that has about 1500hrs since rebuilding them. PO did rebuild but never gave me exact hours so it’s always been a guess. Had some high metal when I did my 1st samples at purchase and that was put down to rebuild. My next change was way down and I have had about 3 more samples since and it all came into normal tolerances.I was changing oil around 150 hrs and labs said it was to soon so next was done at 250 hrs and again told to soon and sample at 350 before changing. This is what I did and they said go another 80-100 hrs, sample and change . This is that result The port side is great and had a rebuild on my watch and is showing fine samples.I don’t get why it jumped so much after it was showing great readings at previous samples.I have not run the 20 hrs yet so it’s sitting with fresh oils from my oil change last week.

[Captain Ralph]

My first SWAG
Allison clutches put some forward pressure on the crankshaft.
There is a thrust bearing (bushing) that keeps the crank from moving end to end. The Allison clutch pushes on this bearing.
Not knowing the details of the rebuild, this is possible.

My second SWAG
Is a bad sample collection.
When I first started collecting oil many years ago, I sent a draw tube down the dip pipe till it hit bottom of the oil pan, then I would draw oil up.
WRONG. This draws settled material up from the bottom of the pan. The tip of the tube has some sediment in it now from tapping the bottom also.
I messed up a few samples this way.

I also used the oil change pump to collect oil.
WRONG. I was also collecting the brass from the oil pump and contaminates in the manifold valves and hoses.

I had a customer tell me, he would pour oil from his oil filters for lab work.
Oh No WRONG.

I now use the dip stick as a guide how far to insert the draw tube.
I now run that oil change pump a while before collecting an oil sample from it.

Last SWAG.
Even the best guy, best process, best equipment, best...
There are Boo Boo's.
Get another sample of warm oil sent in.

[Shaunc]

ThanksI am thinking along the same lines as that I just also had my oil samples done for both transmissions and they were perfect. So not sure if the bearing is an issue but that did cross my mind.I did draw oil through my changing pump which is obviously drawing from the bottom of the oil sump and I also wondered if there has just been a collection of metals over the years that may have caused this. i also did my samples right away and if there were old metals at the bottom, the. This may cause a false reading. I honestly did not think about drawing through a secondary drawdown pipe like you mentioned. I think I will run the 20 hours and do it that way.

[Pascal]

350 hours sounds like a lot especially for DDs. Modern cats (3412a, C32, c30) are 200-250. MTU 16V2000s are 150 hours.

[Sadey]

When is the best time to sample oils; before, right after or a few hours into an oil change? I'm about to take a third sample since purchase. We've put around 500 hours since then, 10/2019.