Oil test

[Gary RVRoamer]

Jimmy makes a good point about baselines. Professional labs such as Blackstone and JG Lubricants maintain statistics for all the samples they process to provide a broad baseline for similar samples, but the most meaningful comparison is to previous samples from your own engine, tranny, etc. That means that you have better information after multiple samples over time, i.e. you can see trends developing.

As an example, I did yearly tranny fluid samples in lieu of blindly changing the fluid in my Allison 3000 every 4-5 years. I could see some metal build-up between tranny filter changes, but the next sample after a filter change (every 3 years) showed it was clean once again.

[jimmy braden]

And I will go one step further in the assertion that there are no BAD initial
(engine ) numbers,, its when something does change significantly that one should be concerned.


I mean one of the biggest reasons to overhaul a motor is oil use and not only will that not show up on a sample it is ALSO relative. If the motor isnt put under significant load frequently, and consumption is 'acceptable' in the current application, that should not be the reason alone to overhaul it.. I think oil samples should just be another tool in the chest that is routinely leveraged so the results can be understood and applied in context (with other tools).

Now having said that I love my ISC SOOO much I will not hesitate to throw 35$ at it a year on top of the OC cost...

ok, im out - soap box open... ;-)

[Mr_D]

Oil analysis can possibly show excess wear, but not something like a valve about to break. Had an analysis done before buying the present rig, showed iron a little high but not that bad. 2200 miles later a valve broke.

[twinboat]

We had Cat dealer SOS oil sampling on our Cat Wheel loader engines from new.

Around 6000 hours, we started seeing high iron in the oil samples, in 2 sister loaders.

SOS and Cat couldn't say where it was coming from, so we had 2 choices, monitor it or tear the engine down. We chose to monitor it.

A few months later one loader lost air pressure. When we pulled the air compressor, the spline drive was stripped clean.

We changed both compressors and canceled the SOS.

[dennis45]

Originally Posted by twinboat

We had Cat dealer SOS oil sampling on our Cat Wheel loader engines from new.

Around 6000 hours, we started seeing high iron in the oil samples, in 2 sister loaders.

SOS and Cat couldn't say where it was coming from, so we had 2 choices, monitor it or tear the engine down. We chose to monitor it.

A few months later one loader lost air pressure. When we pulled the air compressor, the spline drive was stripped clean.

We changed both compressors and canceled the SOS.

And your point is?

[twinboat]

Originally Posted by dennis45

And your point is?

We spent $ for 6 years years of oil sampling for nothing.

[dennis45]

Originally Posted by twinboat

We spent $ for 6 years years of oil sampling for nothing.

From the outside looking in, the samples DID alert you to high iron content so it was doing what it was intended to do.
Did the iron PPM increase? If the compressor drive was failing I'd guess the iron level would have increased. You choose to carry on until the failure became obvious. That's your choice.
But, What if the report showed increasing levels of glycol? Would you continue to monitor or start looking for the source?
Over the years I've reviewed literally hundreds of sample reports. To look at one and say "That's an air compressor drive failing" would be like winning the lottery. You can only make an intelligent guess based on the materials used through the engine.
I am surprised to hear the engine mfg could not at least determine if the contamination was cast iron, hard surface or chrome. But that's another discussion.

Anyway, my point is that if used judiciously, an oil analysis program will pay dividends but it's only another tool in the box and not the end to end all.
Sort of the same logic as your doctor when he sends you to the lab for blood and other body fluid tests. It usually takes more than one sample to zero in on the whole picture. Hopefully the doc can read the reports and add a couple more years on to your life.

[jimmy braden]

Originally Posted by dennis45

From the outside looking in, the samples DID alert you to high iron content so it was doing what it was intended to do.

I tend to agree. It simply comes down to not being able to translate the info into a specific imminent failure. That is not uncommon, but still does not negate the benefits of oil sampling.

Now its quite clear certain Direct drive pumps and geo rotor systems are more prone to wear and early failure than others ( certainly 5.9 cummins), and that moves them to the area of things to check following a high iron sample for example.. .

Are they silver bullets?? nope. Just another tool... ;-)