someone explain oil analysis to me.

[colbystephens]

ok. so i want to get into oil analysis stuff. i'm using amsoil in my freshly rebuilt 6.2 which has like 1500 miles on it. i've seen the kits, but they don't really explain what you're doing or how to do it. can i get a thorough explanation of the benefits and process as well as recommendations about which kit to get? i know i could get one thru amsoil... but i'm open to other options. thanks all.

 

[diesel4me]

all I know...

My brother works at a warehouse that has a fleet of 20+ Mack trucks,and he has to keep them all running and maintained..they send out oil samples to a laboratory that specializes in that kind of stuff,at every oil change---they can tell if the bearings are worn by the amount of zinc and lead in the oil,and how much blowby it has by the amount of soot and unburned diesel fuel in the oil,etc.....thats about my extent of knowledge about it...

I think its a bit overkill for us daily road warriors myself..I can tell when its time to start looking for another motor in my truck just by looking at the magnetic drain plug!--when its fuzzy and has chunks of iron on it,something BAD is about to happen!....or when you drain the oil,and timing gear teeth and valve stem seals end up in the drain pan!... ...$$$$$$$$$$!!! ...

I found a 1" peice of piston ring in the drain pan,on one motor we changed the oil in--a Chevy Caprice wagon with a 307 Olds motor..no wonder it used a qt.of oil ever since it was new every 500 miles!...it seized up about 2 months after that..had 150 thousand miles on it though...

 

[colbystephens]

well, part of my concern is that i want to use amsoil according to the recommendations - change every like 20k or something, but that scares the piss outta me, so i want to just keep good track of what's going on. i want to see this engine do 300k+ easy, so i want to be on top of it. thanks for the tips.

 

[tRustyK5]

20K is a really long way to go for oil in a 6.2. They soot up the oil pretty bad in as little as 3000 miles. I'd probably just run a good quailty 15W40 diesel specific oil and change it every 3K. You don't need synthetics to get a 6.2 to go 300K miles.

Rene

 

[jarheadk5]

A quick down n' dirty summary of oil analysis:

Oil analysis is more properly called spectrographic fluid analysis. A machine called (interestingly enough) a spectrograph is used to "burn" a calibrated amount of the sampled fluid, in this case engine oil. The characteristics of the flame and the resulting smoke/vapor show what materials are present in the fluid, and how much of them.

Oil analysis, in and of itself, isn't the key; it's the analysis of the results over time that really shows what's going on. You have to build a baseline of results (IMO, at least 4-5 analysis reports) before making any changes. Even in aviation, drastic action isn't normally taken on the basis of a single "bad" oil sample - the equipment is operated for a few hours (usually 5 or 10 hours), then re-sampled by another person. If the bad results are still present, action will be taken, but if the new results are back in-line with previous trends, the operator will know the bad results were a fluke (usually caused by the person taking the sample).


IIRC, Amsoil wants a couple filter-only changes during that long oil-change interval. I seem to recall (from about 5 years ago...) their guidance was that if you weren't using OA, change filters and top-off at 3000 and 6000, then change oil and filter at 9000. Personally, I wouldn't do this on a non-DD. Draining the oil gets a lot of crap out of the engine - all that diesel soot, water, acids, dirt, etc. - in short, all the stuff you DON'T want sitting inside the engine for long periods of time.

One final note: If you're gonna do oil analysis, get a Hobbs hourmeter, and base your oil sample/oil change interval on hours of engine operation, not miles.

 

[Blazer1970]

Waste of time and money IMO. Use regular oil and change it every 3K and you will never have an oil related problem. You can't run any oil for 20K miles, period.

 

[jarheadk5]

You can't run any oil for 20K miles, period.

Not true at all. Fleet operators (and a lot of owner-operators) of OTR trucks are getting huge mileage out of their engine oil, because they sample it regularly. They know with scientific accuracy just how much wear material is in the oil, and how well the additive package is holding up. They don't change it until it NEEDS to be changed, and that isn't tied to a specific mileage or operating hours number.

 

[colbystephens]

One final note: If you're gonna do oil analysis, get a Hobbs hourmeter, and base your oil sample/oil change interval on hours of engine operation, not miles.

so if i go to an hour meter, what is the change interval?

 

[jarheadk5]

so if i go to an hour meter, what is the change interval?

When the advice code on your lab results form says "change oil"...


OK, seriously...

Before you get into the new change interval and oil analysis routine, hook-up an hourmeter, note your mileage at that time, and see how many engine hours it takes to rack-up 1000mi. Do this a few times to get a statistical average over different conditions, which will help you relate hours-to-miles when getting started on this. Also, pick a lab you plan to stay with - part of the benefit of oil analysis is the recording and analysis of trends in the results. If you keep changing labs, you'll never build a database of results for the lab to analyze and make predictions on. If a lab doesn't ask you about the variety of oil you're using, move on to the next one - good labs know what results to expect from different oils, and they're able to give better (more accurate) advice this way. Also pick the engine oil you're gonna use and stay with it. This helps with trend analysis too. Now you can begin figuring out a change interval.

Let's just say for the sake of this discussion that it takes 100hrs (all hours here are engine operating hours) to get 1000mi. Pull your first sample at 100hrs and have it analyzed. Next sample at 200hrs, next at 300hrs, and so on. This will allow the oil lab to build a solid base of data for them to look at, and allow them to spot unhealthy trends in wear metals or additive-package loss. At some point (depending on the lab) they may tell you to change the filter, top-off the oil, and resample after a certain timeframe. This basically means the oil is a little dirty, but still has plenty of life (additive package) left in it. Change the oil and filter when they recommend it, and perform this cycle again a few more times. At this point, you should be able to see from your results forms when your engine wants new oil. If you want, you can continue the oil analysis and only change oil when the lab says to. Or, you can look at the previous exercise as simply finding out what a realistic change interval is based on the oil's actual condition, back-off the hours a bit and just change oil and filter at that point, and only sample periodically. Let me give an example, because that sounds a bit confusing even to me:
After sampling every 100hrs (still using that hypothetical figure) and changing oil & filter at the lab-recommended time, you find that the recommended-change interval average comes out to about 600hrs. You could back that off to 500hrs for oil & filter, and change filter & top-off after 250hrs. I'd recommend sampling at the 500-hr oil & filter change just to be safe, and to keep tabs on what the engine is doing internally.

ORRR....... you could forget about hours and just take a sample every 3000mi. when you're draining the oil at oil change time, see how the results come back after a few changes, and go from there.


Now, this ain't cheap. I've seen oil analysis offered anywhere from $10 to $20+ per sample. But if it allows you to get double the time (or more) out of your oil, you will begin saving money at some point. You also reduce the amount of waste oil being generated, if you care about that sort of thing. It's up to you to decide whether the financial investment and "hassle" is worth it.

 

[tch777]

To really go the extra miles on the oil you need to do a bypass oil filter in addtion to the full flow filter on your engine. The bypass filters filter out particles that are very small 10 microns or less, some claim 1 micron or less.

Using this type of filter, OA and filter changes people are going 100,000 miles on an oil change, and are getting over 500,000 miles on their engines. And in the long run they save a bunch of money and time.

Here is a website with all the information you will ever need on oil.
http://www.bobistheoilguy.com/

I have used these guys for oil analysis.
http://http://www.blackstone-labs.com/oil_viscosity.html

Here is a couple different bypass filters
http://www.ralphpwood.com/
http://www.wefilterit.com/
http://www.oilguard.com
http://www.filtrationsolutionsww.com/

amsoil makes some too.

I have a DIY bypass on my PSD, it is not as good as any of the ones I listed above, but with plain old Rotella or Delo I can run my oil for 7,000 miles before I change it, and even then Blackstone said I could go for more. When I run the Rotella T synthetic I can get 10,000 miles out of it.

FYI just dumping the oil evey 3000 miles is wasteful and costly both in $$$ and environment. Read up on Bob's site for more information.

And laugh if you like at the TP bypass oil filters but I know of 3 guys at least running them on their diesels and they get excellent results like the guys who send 3 to 5 times as much on their bypass filters and systems.

Good luck you are on the right road to saving money and wear on your engine. The sites with the best information above is Bob's and Ralph's.

Tim