50l Oil Sample

"I had oil samples pulled on t

"I had oil samples pulled on two 80 hr 5.0 motors. The oil has not been changed in 3yrs.I had spikes in iron , copper, and lead. Use has been infrquent. The compression tests were excellent and the motors run fine at all rpm settings with rated boat performance. Should I be overly concerned?"

Yes. The sampling test result

Yes. The sampling test results indicate premature engine wear from dirty oil that was circulating in the engines w/o passing thru plugged oil filters. The oil just kept getting dirtier. Neglecting to perform oil changes per the mfg. recommendations did not kill the engines but it sure did not help them either. Your engines will be OK with regular oil/filter changes.

Follow the service recommendations for the engines to a "T" and the next samplings will be better. Use Mercruiser oil filters and 15W40 or 15W50 synthetic oil for best results. Add half of a can of SEAFOAM to each engine's oil to clean out built up sludge from the dirty oil.

"Ayuh,....

3 Year Oil Chang

"Ayuh,....

3 Year Oil Changes,..??..??

No Wonder your motor is wearing out.....

Iron is probably the Rings,......
Copper,+ Lead is probably the Bearings......"

no 20 hr service? Assuming th

no 20 hr service? Assuming they had the 20 hr service. I would have put the next 60 hours on during one season. Would you expect me to change the oil before the 100 hour mark?

"In Lee's case, think it i

"In Lee's case, think it is more an issue of time vs hours. Three years will give you a lot of condensation and contamination."

"Lee:

What are your oil pre

"Lee:

What are your oil pressure readings?

"Iron is probably the Rings,......
Copper,+ Lead is probably the Bearings......"

Listen for knocking noises coming from the crank bearings and a steady decline in oil pressure as the bearings wear out.

As a 19 yr. old newlywed G.I. headed to Okinawa, Japan in 2 days in 1970 w/o engine knowledge I blew an engine in a 64 Mustang; overheated--water pump failed and gauge didn't work. I watched in horror as it was disassembled; crank bearings were MELTED and the rings crumbled as each piston was removed. A Ford dealer in Dandridge, TN rebuilt the engine overnight for $85 worth (cost) of parts only. Preacher Vesser was the mechanic and donated his labor.
I LEARNED AFTER THAT LESSON! "

"Just thought I'd add a co

"Just thought I'd add a comment about the importance of not only frequent oil changes, but of changing the oil when it is hot. Changing oil on a cold engine leaves alot of sludge and condensation behind. I've always tried to change oil at the end of the day after the boat has been used for several hours. This also applies to automobiles. Marinas and car repair shops rarely follow this practice and I believe it contributes to increased wear and reduced engine life."

"Excellent point Bob. I take

"Excellent point Bob. I take my waste oil drain tub to the lake when I want to change the oil. I do it right after it is pulled out of the water. Same for the OD."

"Just wanted ya'll to know

"Just wanted ya'll to know I wasn't running this boat without an oil change. It is for sale and has been run very little over the last three years with no change. Based on what I am hearing, I shpould have expected an abnormal test"

"Can you give some specific nu

"Can you give some specific numbers? I've done an oil analysis on around 75 marine engines in the last year, and I would like to see how it compares with some other engines with similar number of hours.

I think you should be around;

Al - 8
Fe - 60
Cu - 20
Cr - 3
Si - 25
Na - 22
Pb - 6"

"dave:

What company do you

"dave:

What company do you use for analysis? I am in snowy SW Ohio.

Guy"

"Guy,
I use Quinn-Cat (Ca

"Guy,
I use Quinn-Cat (Catapillar). They have great service at a very fair price.

Sorry about the snow thing, the weather is great here (if you like skin cancer).

Dave"

"Dave:

Thanks. I know all

"Dave:

Thanks. I know all about the So. Cal. weather from my cousin in Huntington Beach, Ca. She brags about it. "

"Gents,
For starters, you can

"Gents,
For starters, you can't tell anything by comparing one engine oil sample to another. Oil analysis is a trending tool. Multiple samples over a period of time when compared to each other have minor value if you know exactly how to read them. Even then most of the info you are looking at is an indication of normal wear rates when what you are trying to find out is if there are any serious problems. The oil sample ratings from a previous post are an example of spectrographic analysis which can only analyze particles of a few microns, which is where normal wear occurs. If you want to do random samples and get meaningfull information you need to find a lab that does ferrography which examines much larger particles including abnormal wear particles."

"Hoffer,
Have to disagree wit

"Hoffer,
Have to disagree with you. While oil analysis is valuable when used to study wear trends over a period of time in a single engine, a single test can tell you a lot when the number of hours on the oil and the total hours on the engine are known, as they are in this case. I have done enough of these to know what normal levels of wear metals and contaminates are for a given period of operation.

That said, every analysis is subject to interpetation, and it's not a precise indication of what problems exist and thier severity. My recommendation to the original poster is to do a complete engine evaluation, and not rely on a single oil analysis. But I sure wish he would post the actual numbers!"

"DaveN,
I'm not going to

"DaveN,
I'm not going to debate you. I've evaluated several thousand oil samples in my life and I used to own an oil analysis lab, but hey, what would I know?

A ferrographic analysis of a single oil sample will give this fellow 95% of what he wants to know. Its little used in industry because not many labs have the expertise to run the test and it costs 15 to 20 times what a spectrographic analysis costs.

That said, a spectrographic analysis comes back with typical numbers like iron 85 ppm and everyone panics. The same oil sample from a ferrography test will tell you information like the engined is experiencing high rates of normal wear (ie, its getting long in the tooth but is OK) or it might say that sand particles ingested through the breather have become imbedded in the lead/tin babbit of the journal bearings and are scoring the crankshaft. Either condition can produce that abnormal 85 ppm of iron, but one is cause for concern and the other isn't. Spectrographic analysis can't tell the difference, ferrography can."

Both motors had been sitting b

Both motors had been sitting but run periodically and then shut down: Iron:347ppm; Alum:12; Lead:64;copper: 108 ;tin 63

The oil had not been changed

Lee

"Well, the Iron(Fe) le

"Well, the Iron(Fe) level is very high, the lead(Pb) level is also very high, and tin(Sn) is the highest I've ever seen. My guess is that engine won't live anything close to a normal life span. Run it and resample, but it doesn't look good."

"OK, those numbers are high.

"OK, those numbers are high. REALLY high. However, they are not a sure fire indication of a serious problem. With the engine having been run only periodicaly over a 3 year period and the oil not having been changed there are any number of possible explanations for the high numbers. There could be a serious wear condition in the journal bearing and crankshaft signaling an impending catastrophic failure. Or the oil's additive package may have completely broken down due to time and condensation causing it to become acidic which would drive the numbers up without actually being a serious operating condition. Or one of a dozen other scenarios. You just don't have enough information with this type of testing and a single sample.

The numbers are high enough that is the oil pan is easily removed so that an inspection of the bearings and crankshaft can be done, then that is warranted. Usualy in a boat however, that's a major challenge while in a long haul truck its a piece of cake.

If you are determined to diagnose engine condition via oil sampling here is what you need to do.

1) Run the engine up to operating temperature for at least 20 minutes and then change the oil right afterward.
2) Run the engine on the new oil for at least an hour and pull an oil sample. If you can find a lab that does ferrography, have it analysed that way and go with what ever results ger reported.
3) If you can't find a ferrography lab use standard oil analysis at the 10 hour mark instead of 1 and if the numbers came back high (anything over 50) you likely have a serious wear problem.
4) If the numbers are resonably low do another sample at 15 hours and see what the delta is. If the numbers are stable or even rising by 30% or so, no real need for concern. If they spike upward, there is a problem.

All of the above comes with a lot of caveats. Ferrography is the only oil analysis technique that can provide definitive results from a single sample. Spectrographic analysis is usefull only when multiple samples taken at regular intervals are available."

"Hoffer,
Great post. In #3 ab

"Hoffer,
Great post. In #3 above you said that if you do a standard oil analysis to do a resample after ten hours, and that anything over 50 would be high. Would that be for iron or something else? If you are comfortable about elaberating, what would be the levels for some of the other metals?

I appreciate you input on this and understand your cautious approach. I usually only have one shot at doing an analysis and I don't want to read too much into the results, but I don't want to read too little into them either.

Thanks,
Dave"

"I picked 50 as a decent start

"I picked 50 as a decent starting point in the conext of the last sample. In thinking about it, that might be too high. Again, its almost impossible to come up with any valuable conclusions without repetitive sampling. I also meant to mention that samples should ONLY be taken from hot oil, never cold. There's no real rule of thumb I can give you for a single sample...I would have to go into a discussion of engine types (diesel? gas? aluminum block? steel block?) and on and on. Plus I'd have to brush up on the data since its been years since I was involved in this.

There was a company in Cleveland named Predict. If they are still around they do ferrography. A single sample is probably $100 but you will get the information you seek from it."

Thanks. I will research ferrog

Thanks. I will research ferrography.

"David,
Thanks for the educat

"David,
Thanks for the education on oil sampling. I also found out that the oil was pulled not from the oil pan but from the filters which I feel would not be a qualified sample.

Lee"

"Lee:

If you are buying the

"Lee:

If you are buying the boat, you could show the sample results to the owner and bargain down the price since there is no way of determining the actual amount of wear and tear on the engines w/o tear down. Pulling samples from the oil filters resulted in erroneous test results due to the concentration of contaminants found in three year old oil/filters. You MAY be getting solid engines or PREMATURELY worn engines; caveate emptor which you are!

Boys, the snow is dissapearing here. Start your engines!
"

Get a proper filter cutter and

Get a proper filter cutter and cut the filter open with the seller....bring a new filter and a magnet with you .....show him the shiny stuff in the pleats and negotiate...

A new 5.7 (350 cubic inch) 4 Bolt main crate Long Block is $1479 from Jegs.

I say this boat is the perfect candidate for an upgrade of 45 cubic inches and 30HP