I have beeen running synthetic for a while in my truck and I run the oil up to 12000 miles before changing. I change the filter and top off the oil every 3000 miles.

Every 3000 miles I take a sample and send it off to a lab and have it analyzed. The sample shows perfect and still useable at 12000 except for one small thing. The longer I run the oil the higher the concentration of silicon gets. High concentrations of silicon usually mean dirt is leaking past the airfilter and getting into the oil. I would assume the oil filter is not capable to filter out the small grains of silicon.

This truck is a 2000 and I only used motorcraft air and oil filters so I know there is nothing wrong with the air filter and I change the air filter every 15000 to 18000 miles.

Any thoughts on the silicon. I am seriously thinking about going back to using normal oil and changing the oil and filter every 3000 miles.

 

I've used oil analysis lab services, so I know what you're talking about.

Is the silicon level still withing acceptable limits? The lab should be able to advise you there. If it's still acceptable maybe you need'nt worry.

Your air filter is probably performing as designed, but with your extended oil change interval what it lets by has a cumulative effect.

Perhaps a specialty aftermarket air filter like K&N would help. Since you are doing analysis, you would be able to evaluate it's effectiveness.

Of course if you consider the cost of oil analysis and the premium price of synthetic oil, extending intervals probably isn't so economical.

Since you must by now have a good baseline of information from your synthetic analysis, it would be interesting to switch over to conventional motor oil and continue the sampling. Comparing the results of the normal wear metals such as iron, copper, chromium and lead would be interesting.

The oil formulated specifically for diesel engines like Chevron DELO 400 or Shell Rotella T (and others) are the highest quality conventional oils. They are made for extended change intervals in the big trucks and they are API SJ rated for gasoline vehicles.

 

[font size="1" color="#FF0000"]LAST EDITED ON 06-Jul-01 AT 01:17 PM (EST)[/font][p]at the first test silicon is at 21 ppm and this is acceptable.
A sample tested later showed 35 ppm which is still acceptable but warrants keeping an eye on it.

I know someone else that runs the same tests and he gets numbers like 7 and 9 ppm for silicon.
THere is a big difference between him and I and we drive the same truck......

I think he uses K&N air and oil filters though.

I did make one change this time around when I changed the oil. I installed a remote dual oil filter setup. I am now running 2 full size oil filters instead of those retarded small filters. One filter is a motorcraft and the other is the Purolator 1. They are both in parrellel so if the High filtering Purolator 1 plugs up I still have the other filter doing its job. I think the Purolator 1 filters 95% of all ##### out of the oil

 

[font size="1" color="#FF0000"]LAST EDITED ON 06-Jul-01 AT 09:35 PM (EST)[/font][p]The truck I was doing oil analysis on was a turbocharged diesel.

It had a large oval shaped metal cannister type air filter.

Since it gulped so much air I used to smear silicon grease on the rubber gaskets on either side of the filter to make sure that no contaminates bypassed the filter by getting sucked in through the gaskets.

Mentioning silicon grease reminded me that the contaminant we are discussing is silica, not silicon. Dirt and sand contain silicates. I think silica is what they use in glass making, which is why it is so abrasive.

Anyway it would be interesting to find out if dual filtration will cut down on the silica in the oil, or if is too fine to filter out.

Hope you post back with results from your next analysis.

 

Right on the silica, that's sand/dirt I think. Silicon is what they make your computer out of and Silicone is in most of the gasket sealants used today.

1977 Ford F-100
400m/c6/4:11/Gear Vender O.D.
Crane hydralic roller, forged, ported polished,Deamon,Edlebrock, yada, yada, yada
280,000 miles
Stock on the outside
modified/rebuilt everything

 

I would like to get an oil analysis. How would one go about getting one? How much does the analysis cost?


Xaviar

 

You are right but I have seen two tests down by 2 different companies and both use the term silicon and not silica. Definition of silicon on test form states "Dirt that has bypassed air filter"

 

It costs 21.00
http://www.oillab.com/bestoil.html

 

[font size="1" color="#FF0000"]LAST EDITED ON 10-Jul-01 AT 02:15 PM (EST)[/font][p]greenpus,

I was mistaken. I just looked at my last oil analysis report and it too, says *silicon*. so solly!

FWIW: My silicon level was 17 ppm after 3,000 mi on dino oil with Fram oil and air filters. That was on my '81 F250 5.8L, the only test I've done so far. I have since changed to AC/Delco oil filter.

Guys:
You can get oil analysis though your local Caterpillar dealer. Pick up the sample jars at the parts counter. Last time was only $12 or so.

The lab I used was:

Quinn Company (CAT)
P.O. Box 12625
Fresno, CA 93778
(559) 891-5499
Fax (559) 896-8725

 

-begin quote-
Every 3000 miles I take a sample and send it off to a lab and have it analyzed. The sample shows perfect and still useable at 12000 except for one small thing. The longer I run the oil the higher the concentration of silicon gets. High concentrations of silicon usually mean dirt is leaking past the airfilter and getting into the oil. I would assume the oil filter is not capable to filter out the small grains of silicon.
-end quote-

basic chemistry.
synthetic oil contain silicone, which is an organic compound
in which some or all carbon atoms have been replaced
by silicon atoms. ( the organic compound part above can can be a man made compound instead.)
Now the basic chemistry part.
heat the synth oil and put it under lots of pressure and the
compounds break down into ....guess what..silicon+all the other
stuff in the compound(s).
If you heat silicon in the presence of oxygen, it oxidizes and becomes silicon oxide. ( sand on sand paper.)
silica/silicate usually refers to silicon oxide.
great stuff for inside an engine.....
What happens is some oil gets past the rings, then burns during the combustion cycle in the cyclinder. Most then goes out the
exhaust, but some trace ammount gets blown past the rings in to the lower end of the engine ( oil is being slung everywhere in there when running) most of this blowby gets sucked out by the
pvc valve circuit and gets another chance to get blown out the exhaust, but some slight amount mixes back in with the slinging oil. This causes the silica/silicates level in the oil to slowly creep up.

high milage engine=lots of blow by.
you figure it out from here.......

here's an interesting note:
on 2-cycle model airplane engines castor oilhas been used for years
because it will mix with methanol. It's a gooey mess to clean
of the plane after flying it.
Synthetic oil can be made to mix with Methanol.
makes clean up easy, but leaves glassy deposits on glow plugs
( glassy because it's glass... ).
What happens when a piece of that glassy deposit comes loose....
Sounds like a grain of sand in the wrong place.....
The cause of the deposits on the plug is synthetic oil in the combustion chamber.

 

[updated:LAST EDITED ON 11-Mar-02 AT 01:14 PM (EST)]I have been running the dual filter setup for awhile and with the Puralator 1 it seems to have dropped the silicon content. The drop was very small so I really can't say the filter helped or not.
It seems to be staying under 25. I now run the oil up to 15,000 instead of 12,000.


>Quote by horsepuller
>
>Anyway it would be interesting to find out if dual filtration will >cut down on the silica in the oil,
or if is too fine to filter out.

Hope you post back with results from your next analysis.

 

I had an oil analysis done on petroleum oil that had
3,000 miles on it and it came back in bad shape with
the lab recommending that I change it at once. I then
ran Amsoil synthetic with their oil filter and had the
oil checked again at 6,000 and the oil came backin good
shape. Since then I have added Amsoil air filter and their
by-pass oil filtration system on my 92 302underpowered F150.
I have not yet done another oil sample, but will be in the
future when it is do.

 

>I had an oil analysis done on petroleum oil that had
>3,000 miles on it and it came back in bad shape with
>the lab recommending that I change it at once. I then
>ran Amsoil synthetic with their oil filter and had the
>oil checked again at 6,000 and the oil came backin good
>shape. Since then I have added Amsoil air filter and their
>by-pass oil filtration system on my 92 302underpowered F150.
>I have not yet done another oil sample, but will be in the
>future when it is do.

Hey Horsepuller,
You need to ban this guy soon. He is on every mesasge thread selling this crap!

 

To me, running oil for an extended period and using lab testing to determine when it should be changed doesn't make economic sense, at least on anything smaller than a semi tractor or railroad diesel that holds many times that amount of oil that a pickup might hold. My truck's engine holds six quarts of oil, so each $12 test would add $2 to the price of each quart of oil. If a person goes 12,000 miles between changes and tests every 6K miles or so, that's $4 a quart more, or the price of fresh Mobil 1 at Wal Mart.
Am I missing something here?

I'm not disageeing that oil testing can provide useful information related to engine, oil and air filter performance. If that alone is worth the testing cost to someone, so be it, but it's not saving anyone much money, IMO.

I use synthetics because I've had good results with them and the cost is secondary. Even changing the oil I use every 5K miles or so, I spend a lot more on premium beer and wine and the steak instead of macaroni and cheese than on premium synthetic motor oil.

How's that Amsoil taste, anyway?

 

If you read my text you will see I am not trying
to sell you anything. I was just telling my
experience with synthetics versus petroleum oil.
Just because I mentioned Amsoil by name doesn't
mean you need to get your shorts in a bundle.
People mention Mobil 1 by name and nobody throughs
a hissy fit. With that said lets drop this childish
behavior.