Renegade_Master
Well-Known Member
Called engine technos, what are the dangerous things to look out for in an oil analysis? Would lead worry you?
Lube analysis
- Thread starter Renegade_Master
- Start date
totopalm
Well-Known Member
Cerainly would 'specially if from big end bearings or main
bearings /forums/images/graemlins/frown.gif
bearings /forums/images/graemlins/frown.gif
Renegade_Master
Well-Known Member
what about soot?
totopalm
Well-Known Member
Dunno!
Renegade_Master
Well-Known Member
someone said soot could mean burnt fuel gases from the combustion chambers getting past pistol rings tut bottom end
jcmmarine
Well-Known Member
There are a number of element to lub oil testing, a few of the more important are as follows.
Fuel dilution. the amout of fuel that has found its way into the oil, 3% can significantly lower the viscocty to a level that can reduce protection, but more importantly, 5% can result in a crankcase explosion.
Acidity/Alcalinity. Exteames of either an cause corrosion and degreagation of components.
Water content, lowers viscocity, reduces lubrication. Even worse is salt water leaving salt in the oil when the water evaporates. Have you seen pictures of bearings that look like crazy paving, that is often caused by salt in the oil.
Carbon content, caused by blow past, enventualy turns oil into grinding paste.
That is only a very brief coverage of the main contaminants, there are books on the subject.
Fuel dilution. the amout of fuel that has found its way into the oil, 3% can significantly lower the viscocty to a level that can reduce protection, but more importantly, 5% can result in a crankcase explosion.
Acidity/Alcalinity. Exteames of either an cause corrosion and degreagation of components.
Water content, lowers viscocity, reduces lubrication. Even worse is salt water leaving salt in the oil when the water evaporates. Have you seen pictures of bearings that look like crazy paving, that is often caused by salt in the oil.
Carbon content, caused by blow past, enventualy turns oil into grinding paste.
That is only a very brief coverage of the main contaminants, there are books on the subject.
petem
Well-Known Member
[ QUOTE ]
Called engine technos, what are the dangerous things to look out for in an oil analysis? Would lead worry you?
[/ QUOTE ]
I would be on the lookout for oil testers that expect you to interpret the results!
Called engine technos, what are the dangerous things to look out for in an oil analysis? Would lead worry you?
[/ QUOTE ]
I would be on the lookout for oil testers that expect you to interpret the results!
jcmmarine
Well-Known Member
If you do not know what you are looking for or at, pehaps it is best not to look.
andy_wilson
Well-Known Member
You will always get some soot in the oil, it's what else is found with it that points towards problems.
Soot is often associated with upper cylinder wear, and often the cause is poor injector spray, timing or other related fault that causes incompete burning, with diesel washing soot past the rings.
Soot, diesel, iron and chromium in the sample are all indicators of this problem.
Problem is you need base oil analysis and earlier, comparative readings before they make real sense.
Soot is often associated with upper cylinder wear, and often the cause is poor injector spray, timing or other related fault that causes incompete burning, with diesel washing soot past the rings.
Soot, diesel, iron and chromium in the sample are all indicators of this problem.
Problem is you need base oil analysis and earlier, comparative readings before they make real sense.
D
Deleted User YDKXO
Guest
Clive, I've had 3 oil analysis done and the one 'failure' involved excess amounts of Copper (Cu), Iron (Fe) and Molybedum (Mo). The engineer attributed the excess Cu and Fe to general wear in bores, piston rings, valve guides etc. The Mo reading was a bit more of a mystery but eventually he concluded that it could only have come from engine oil additive like Molyslip
andy_wilson
Well-Known Member
Molybdenum is a fairly standard part of lube oil additive pack, and also found in piston rings, but if rings were the problem, Chromium would be a primary indicator with Molybdenum as a secondary indicator.
High oil consumption can leave Molybdenum levels high, but also Boron, Silicon, and Chromium, which could leave the unwary thinking that coolant was getting into the oil.
Copper and Iron tends to reflect problems in Transmissions and Hydraulics, though could be an indicator of valve train problems.
High Iron levels are typical in leisure boat engine oils. Long periods of standing followed by hard cold starting makes this quite normal, if a little undesirable.
High oil consumption can leave Molybdenum levels high, but also Boron, Silicon, and Chromium, which could leave the unwary thinking that coolant was getting into the oil.
Copper and Iron tends to reflect problems in Transmissions and Hydraulics, though could be an indicator of valve train problems.
High Iron levels are typical in leisure boat engine oils. Long periods of standing followed by hard cold starting makes this quite normal, if a little undesirable.
jcmmarine
Well-Known Member
Be careful; there is a diffrence between oil analysis and oil particulate analysis. In oil analyisis you are looking at the condition of the oil. In oil particulate analysis you are examining pre-filtered oil, from filter bodies, sumps and sometimes magnetic drain plugs.
The particulates examined can be very useful in directing towards paricular component wear. However. unless regularly done and sumps and filters regularly cleaned, it can be missleading.
In new engines there is a gereat deal of wear as it runs in, but metalic pariculates should not get past the filters. However, if the engine has never been properly drained, flushed, then drained again during servicing. (eg just lazily sucking out the sump top layer of oil through one of these vacume units down the dip stick) There is probably lots of particulate still laid in the bottom of the sump from when it was new.
Sample this and test and it will frighten you when there may not actualy be a problem.
The particulates examined can be very useful in directing towards paricular component wear. However. unless regularly done and sumps and filters regularly cleaned, it can be missleading.
In new engines there is a gereat deal of wear as it runs in, but metalic pariculates should not get past the filters. However, if the engine has never been properly drained, flushed, then drained again during servicing. (eg just lazily sucking out the sump top layer of oil through one of these vacume units down the dip stick) There is probably lots of particulate still laid in the bottom of the sump from when it was new.
Sample this and test and it will frighten you when there may not actualy be a problem.
