Engine oil analysis - Worth it or No?

Canopy Locked

Canopy Locked

Well-Known Member
Joined
5 Dec 2006
Messages
1,115
Location
Nth East Scotland
Visit site
Survey and sea trial tomorrow & Tuesday of a 2009 16m boat. She has two Cat C18.

Given that these are expensive lumps, what information will an oil analysis provide? Is it actually worth it?

If yes, how should the sample be taken and to whom should the analysis be entrusted?

Many thanks for any pointers
Rob
 
I had Finnings test my oil last year. As the are Cat Agents they will be able to assist with other requirements. For what you are buying the cost is minimal and it will tell you precisely what he oil contains and whether a change is required.
 
robmchugh said:
Survey and sea trial tomorrow & Tuesday of a 2009 16m boat. She has two Cat C18.

Given that these are expensive lumps, what information will an oil analysis provide? Is it actually worth it?

If yes, how should the sample be taken and to whom should the analysis be entrusted?

Many thanks for any pointers
Rob
Click to expand...

If the engines have had proper Finning UK service they will have had SOS. Scheduled oil sampling as part of there annual service, the results should be held by Finning U.K.
As far as I'm aware Caterpillar and Finning are the only UK company to do this , both in the marine and Industrial market .

I carry out many pre purchase engine inspections and always offer oil sampling as part of this.
The feedback I can give based on the last 5 pairs of engines I've sampled,
3 pairs out the 5 failed, I won't go into too much detail as my clients are on here but 1 out the 5 rejected the boat based on a very high aluminium content on a D6 with just 175 hours on it.

Before you decide the engines must have been run a minimum of 30 hours in the same oil for it to give the best results , sampling new oil is a waste of time.
Some boat dealers service the engines of there stock boats prior to sale, this of course falsifies the result so the only answer to a factual result Is to run it for 30 hours then sample each engine.

For the sake of £60 on a pair of C18s it's well worth it, sound like a big boat to me .
I'd be employing the right people to survey the boat , certainly the dealer for the engines assuming this is an expensive boat .
 
superheat6k said:
I had Finnings test my oil last year. As the are Cat Agents they will be able to assist with other requirements. For what you are buying the cost is minimal and it will tell you precisely what he oil contains and whether a change is required.
Click to expand...

You can buy the sample kits from Finning , I carry them and am assigned to there oil Lab as a registered client.
 
The answer is yes and by Finnings who can supply you with loading time history as well.
Recognise most value is in data comparison with (any) previous tests.
Remember gearboxes too as they are often neglected.
 
+1 An oil analysis once saved me from buying a very nice boat with shagged Cat engines which the seller had tried to conceal as being shagged. As volvopaul says, the oil has to be representative of the engine's condition and therefore has to have been in the engine for at least 30 hrs of operation. One other tip a MAN technician gave me this year is to make sure that you or whoever is taking the sample does not remove the oil from the base of the sump where excess debris may have collected in which case the result may be adversely skewed
 
I'd suggest that even if the oil hasn't done 30 hours, it would still be worth testing it. If the results are clear then I agree it tells you little about the state of the engines. But, if there's aluminium or whatever in the oil @ 20 hours then the engine really is knackered or somebody has been ripping off the previous onwer.
 
Last edited:
What does "high aluminium content" from a sample mean back in the real world.
Scuffed pistons? Oil not changed?
 
A friend who owns a single engined light aircraft with an IO-540 lycoming used to send his oil off for analysis at every 50 hr check and felt much comforted by the results. One day, however, he decided to conduct an experiment and sent a sample of oil, taken from the same oil change, to three different companies for analysis. Guess what? He got back three completely different results. These days, he cuts open the oil filter to look for obvious particles and checks that the waste oil does not look like a gallon of metal-flake paint.
 
FWIW, I also think that oil analysis is a bit overrated.
I'd be curious to hear from the pros like volvopaul how often they came across an engine performing flawlessly, reaching its rated rpm, not smoking, etc. whose oil analysis was a total mess.

And even then, what sort of recommendations were given?
I mean, even assuming that the punter rejected the boat, what would be the best suggestion to give to the current owner?
Replacing oil and filter asap, I suspect...
 
MapisM said:
FWIW, I also think that oil analysis is a bit overrated...
Click to expand...

A good point, and possibly some "up-selling" of a service by the engine makers/suppliers. Certainly long term monitoring is useful in some applications. Maybe not so much for smaller leisure craft engines. You could waste a lot of money dealing with every anomaly shown up by oil analysis.
 
For those of you who think it's not necessary to take oil samples when investing in something like a £250 k 10 year old boat ask yourself what would another £60 matter on the survey costs bearing in mind one day you may be faced with a £25 k bill for a rebuild or new unit .

Sadly the owner of the said boat is no longer with us , the boat is now under offer again .

The service history said it all, 2 services in 10 years, boat been stood for last 2 and a half years with no attention at all, one. Engine perfect on sample test. The other a walk away deal breaker.
If you just looked at the low hours 175 in 10 year some you would normally think the hours and wear factor not an issue , the samples don't lie.
 
+1 to what VP said. My Cats have oil samples taken by the service firm at each annual service and they keep a history of the results
 
jfm said:
+1 to what VP said. My Cats have oil samples taken by the service firm at each annual service and they keep a history of the results
Click to expand...

I will also add that samples are used by manufacturers and analysis is used to develop manufacturing.
Samples will be compared engine to engine , for example should a part have been made incorrectly the metal particles would show up in the oil, the manufacturer would then look into this and make a recall ,
This may have shown up in the soft block issue with the 3126 a few years back .
 
You must log in or register to reply here.

Share this page

Top