Engine Oil Testing?

[Tim Good]

I have a Perkins M90 engine in my boat from 1996. Although it works perfectly well, runs smoothly and I have plenty of spares, I heard you can send oil away to have it analysed.

Has anyone ever done this and is it much of an indicator as to how much life your engine has left. If so how long / engine hours after an oil change should I wait until I do?

 

[vyv_cox]

I used to be responsible for oil condition monitoring on a wide range of equipment. You will see all sorts of claims made for metals levels but the reality is that results can be influenced enormously by the way the sample is taken. One-off sampling for fault detection is pointless, the only way to use the technique effectively is to accumulate data in a very controlled way, by sampling at regular intervals through the life of the oil. There might be some value in testing for water, TBN, TAN in commercially used boats but for yacht engines it is all a bit pointless, and expensive.

 

[Tim Good]

I used to be responsible for oil condition monitoring on a wide range of equipment. You will see all sorts of claims made for metals levels but the reality is that results can be influenced enormously by the way the sample is taken. One-off sampling for fault detection is pointless, the only way to use the technique effectively is to accumulate data in a very controlled way, by sampling at regular intervals through the life of the oil. There might be some value in testing for water, TBN, TAN in commercially used boats but for yacht engines it is all a bit pointless, and expensive.

Fair points. I'm actually quite surprised at how clean the oil is. It was changed in August and maybe has 40 hours on it and it is still as clean as the day I put it in. Never known a diesel engine do that.

 

[sailorman]

Fair points. I'm actually quite surprised at how clean the oil is. It was changed in August and maybe has 40 hours on it and it is still as clean as the day I put it in. Never known a diesel engine do that.

In fixed plant it would be doing in excess of 40 hrs per week & probably flat out too

 

[KenMcCulloch]

Fair points. I'm actually quite surprised at how clean the oil is. It was changed in August and maybe has 40 hours on it and it is still as clean as the day I put it in. Never known a diesel engine do that.

We have been pleasantly surprised how long the oil in our 33y.o. Bukh DV36 stays clean after a change. We would normally cahnge the oil just before hauling out and the oil remains translucent well into the new season.

The engine is subject to the usual sailing yacht abuse by being used for < an hour at each end of a typical day. My theory is that indirect cooling makes a huge difference, the engine gets up to temperature fairly quickly and runs quite a bit hotter than a raw water cooled engine.

 

[VicS]

We have been pleasantly surprised how long the oil in our 33y.o. Bukh DV36 stays clean after a change. We would normally cahnge the oil just before hauling out and the oil remains translucent well into the new season.

The engine is subject to the usual sailing yacht abuse by being used for < an hour at each end of a typical day. My theory is that indirect cooling makes a huge difference, the engine gets up to temperature fairly quickly and runs quite a bit hotter than a raw water cooled engine.

I think there has been some changes in the oil, or fuel ......... I have run small diesel cars for some time. New oil was always black again pretty soon after an oil change. 3 or 4 years ago things suddenly changed with new oil staying clean looking for much longer. Same car. no changes to that whatsoever. Same brand of oil too AFAIR

 

[RichardS]

I think there has been some changes in the oil, or fuel ......... I have run small diesel cars for some time. New oil was always black again pretty soon after an oil change. 3 or 4 years ago things suddenly changed with new oil staying clean looking for much longer. Same car. no changes to that whatsoever. Same brand of oil too AFAIR

You will certainly notice the difference going from mineral to synthetic oil, as will the inside of your engine which will not be stained yellow, but it doesn't sound as if that is the case here. Presumably semi-synthetic will be somewhere between the two but I don't have much experience of semi.

Richard

 

[ianj99]

I think there has been some changes in the oil, or fuel ......... I have run small diesel cars for some time. New oil was always black again pretty soon after an oil change. 3 or 4 years ago things suddenly changed with new oil staying clean looking for much longer. Same car. no changes to that whatsoever. Same brand of oil too AFAIR

Its down to cleaner burning fuel - most has some biodiesel in it these days which also helps.