Oil Analysis Results are in

[TROUBLE]

Got my oil results back yesterday from motor check. It says "all samples appear free of external contamination. Analysis indicates proper performance of the lubricant and unit"

OK My question is, there is a significant difference in the port and starbord engine. Maybe someone here thats more familar can help me understand.

STBD ENGINE (all parts per million) 8-53n
aluminum 0
chromium 0
copper 8
iron 34
lead 0
tin 0
silicon 7
potassium 0
sodium 38

PORT ENGINE
aluminum 0
chromium 1
copper 15
iron 38
lead 8
tin 4
silicon 19
potassium 0
sodium 17

same hours on each engine, same oil, same change interval. Is there something going on?

thanks in advance as always
ART
TROUBLE

[jim rosenthal]

One engine needs a low-salt diet

I think the trends are more important, as in repeated samples over time. Can anyone who has done these routinely comment on this? I have not done them. I don't know what the acceptable variation ranges are.

[MikeP]

The results are that the samples are within acceptable limits. Don't make yourself nuts over the difference between the two different engines. Engines are different, just like people.

As Jim said, do periodic samples and look at any trend. One-time or first-time samples tell you almost nothing of any value because there is no baseline to compare to. There can be great or terrible results which do not accurately reflect what is really going on. For example, an engine that hasn't been run in a long time can have some surface rust on the cyl walls. This rust is gone almost instantly when the engine starts but it will show a high iron content in the sample which can lead to an improper diagnosis of a problem where none exists.

OTOH, a common boat selling technique is to do a fresh oil change, have the oil sampled and then show the "perfect" oil sample result to the prospective buyer.

So, the only way an oil sample serve any useful purpose is to do them periodically under the same operating conditions. THEN the results can actually be used to help monitor what's going on.

[magnawake]

Low salt..ha-ha. I was thinking the same thing. Potassium? At least you havent been feeding them bananas. Yeah, If you let it go long enough, you will get some wear products. I'm not an expert but they look good to me. I always thought the same thing about changing the oil and pulling a sample, then bragging about it. Seems like to many variables involved. If you did have a really bad problem, the numbers would be way different from other engine. Chunks of metal would be on the bottom of the sample bottles.

[Boatnut]

You have no idea where the engine was at when you started, the only thing an analysis on a used engine might tell you is if there is extremely high bad numbers, possibly indicating failure is soon to come. The first oil analysis on any engine is only to establish a base line number. If the engine maintenance is not strictly and timely maintained, you are wasting your money to do an analysis. You need to not only do the maintenance, you also have to keep accurate records of running hours on the engines, including warm up time at the slip.

[TopHattandTails]

The reason to do periodic, consistant oil samples is to demonstrate to your insurance company that you maintained the motors in case of a claim.

[Boatnut]

The reason to do periodic, consistant oil samples is to demonstrate to your insurance company that you maintained the motors in case of a claim.

Not really true, if you do the propper maintenance, and keep acurate records. You would be surprised what the analysis shows, and the cost savings if something if wearing out, and is replaced before the problem becomes catostraphic.

[Bill Herrin]

Lots of people here don't put much stock in oil analysis, I do. I ran a bus conversion with an 8-71 for ten years with a lot of travel involved, it had an engine oil cooled 300 amp alternator direct driven. At an oil change in Phoenix the oil came back with a major increase in bearing metals showing, the service manager at Sinatras recognized the mix and said you'r losing the bearings in your alternator.... he was right and we rebuilt the alternator. If we hadn't the possibility of letting 13 big ball bearings loose into the 'pin ball machine' of gears could have a catastrophe for us. No 'in frame' in that rebuild.