Engine Oil Analysis

I have 2 different situations that I am thinking might be useful to obtain an engine oil analysis.

The cost is $40

I have recently placed an older (quality) rebuilt 4.2 in my 420G, its use since rebuild is unknown

The other engine is in my 4wd , and has 335,000km, obtained by me with 280k on the clock

why I am considering this is it is the best way of detecting any failures that allow mixing of oil and coolant, or combustion gases. Often (imo) an engine will function for a long time without giving clear and obvious signs, but it is killing your engine

detects the presence of various metals in your oil, that are telltale of excessive wear in bearings, rings, etc

detects dilution of oil by fuel (can be problem with our older vehicles)

to make it most worthwhile, it would have to be done semi-regular

here is some blurb…anyone done this…think it worthwhile?


Yes, absolutely worth it for peace of mind if you have reason to believe there is a problem. I put in a magnetic drain plug at around 12k miles on my rebuilt engine. At the next oil change, found some chunks of metal that just about made me pee my pants. Got a clean catch of the oil and took it in. Results came back with no problems. Did it again at next change - about 3k miles - also came back all good. Cutting open the oil filter both times showed nothing. Believe the problem to have been left over debris from inadequate cleaning.
Now I have peace of mind and 22k miles with no problems.
Not the same as you’re high mileage engines, but still nice to have the info. Lots of truck fleets use this as part of their preventive maintenance program with good results.

Well worth doing! A good analysis will show bad levels of things like Cu, Fe, Si, Mg, Pb etc, and possible fuel comtamination. They should also suggest where to look for the source of the problem - Si could be dust, sand ingestion, or even from Silicon gasket stuff overdone; lead, copper can come from bearings.
Here in Oz ALS do this work, but ask for a FULL analysis -