Engine Oil Analysis

[John D]

This is for real gear heads, including me.

After limping 7,600 miles across the American continent and back with a rusty fuel tank, numerous clogged fuel filters and engine stopages, the tank was finally replaced with a brand new one, problem solved. The engine oil was analyzed to check for damage. After the next oil change, it will be analyzed again. This is a 1999 F-150 V6 4.2L with 5 speed manual with about 80,000 miles hauling a Keystone. We also wanted to see if 10,000 miles was a reasonable oil change frequency.

Total on this oil was 10,000 miles with one quart make up oil. Mobile 1 5W30

Any comments will be very much appreciated. The technician does not know for certain what the results mean. We will know more after the next analysis. Any opinions about these first results will be of interest. We have some smart people in this forum, so lets see some ideas.

John D

 

[cwdtmmrs]

John,I belong to a Rolls Royce forum as well and these guys are always doing oil analysis. Here is a link to an article from the club news letter. http://cloudsociety.org/pdf/post55_mag/2010.1.pdf

Hope this helps,

CWD

 

[Barko1]

The TBN seems to indicate that your oil was worn out and the high iron reading wouldn't put a smile on my face .
What is the recommended oil change interval, 4000? I guess I don't understand why you are doubling the oil change interval when putting the engine through severe service


This is for real gear heads, including me.

After limping 7,600 miles across the American continent and back with a rusty fuel tank, numerous clogged fuel filters and engine stopages, the tank was finally replaced with a brand new one, problem solved. The engine oil was analyzed to check for damage. After the next oil change, it will be analyzed again. This is a 1999 F-150 V6 4.2L with 5 speed manual with about 80,000 miles hauling a Keystone. We also wanted to see if 10,000 miles was a reasonable oil change frequency.

Total on this oil was 10,000 miles with one quart make up oil. Mobile 1 5W30

Any comments will be very much appreciated. The technician does not know for certain what the results mean. We will know more after the next analysis. Any opinions about these first results will be of interest. We have some smart people in this forum, so lets see some ideas.

John D

 

[UglyScout]

I guess I don't understand why you are doubling the oil change interval when putting the engine through severe service


Ditto. I run 7500+/- miles to an oil change but I have 3 gallons to work with. If I knew I was beating up my engine/oil I'd change it much closer to the recommended interval or even less than the recommended.

 

[Stan@FourWheel]

I have never thought about getting an oil check out like that ?

I used to use the Mobil 1 synthetic oil in my older BMW in the late 80's.

Kinda remember everyone saying that you could go much longer between the oil changes running the synthetic oil.

But the cost for that stuff is high and I just don't personally see the benefit to the extra cost. If you had a high performance car, or a race car, it might be worth it.

But i'm not sure it is needed for a regular 1/2 ton truck ?

I also have a Ford F-150 and it has plenty of power, dual exaust, 5.4L V-8, K&N air filter, it gets up and goes when I want it to. I take care of it, but im not afraid to use it either.

On all of my vehicles over the years I have tried to make a practice of keeping the car/truck tuned up, keeping the air filter clean, and changing the oil every 3500 - 4000 (+ or -).

I have been using Valvoline for years and have never had any probelms.

But i'm sure oil brand is like buy a particular truck brand, everyone is going to have something they like or prefer.

The normal oil you get at the automotive stores these days (any brand name) should be pretty good stuff for an average driver.

Keep your air fitler clean.

Keep your oil & filter clean and change every 3500 - 4000 miles.

Keep the engine clean & tuned up.

... and drive it until it dies.



What else can one do ?

If the oil report comes back really bad, what are you to do ?

Sell the truck ?

Rebuild the engine ?

If it is running good now, just keep on trucking ...






.


.

 

[Mark W. Ingalls]

Just my opinions, based on thirty five years of working around farm machinery and industrial equipment...

The iron came from the rusted steel tank. There may have been so much of it that you raised the oil's friction coefficient.

One reason we can now go for such long intervals between changes is the large sump volumes. Oil doesn't just wear out from heat (friction), it gets dirty. Dirt not only raises the viscosity but also the coefficient of friction. (BTW, cast iron is hard on machine tools because it is crystalline, not ductile; rust is pretty abrasive for the same reason.) Since you don't have a larger sump, I would not go for the enormously long change intervals.

Your bearing elements (copper, lead, tin) are not *all* high, just copper & lead. So either your plane bearings are not suffering yet, or they're already toast. (Much of the tin is a hard surface plating that is cushioned by the soft copper.) The simple way to tell if they're worn is to look at your oil pressure. Since the tin level is *so low* I wouldn't worry about the plane bearings too much.

Here is an excerpt from CWD's linked article:

Generally, ... one would be most concerned about copper, lead and tin (from the bronze and babbitt bearings), iron (from the cylinder walls and crank and cam shafts, pistons and piston rings, etc.), and aluminum (from the pistons, assuming they have been changed from cast iron). You will normally not see chromium, nickel, titanium, vanadium or silver ... although the spectrographic analysis checks for these metals. Brass is a little harder to distinguish as it is principally an alloy of copper and zinc. While copper is clearly shown in the analysis, zinc is masked by its high concentration in additives. Incidentally, [bearing composition] is generally about .6% lead, 4.3% copper and 87% tin. It contains 8.5% antimony as well, which is generally not reported.

Magnesium, calcium (alkalinity improvers — to prevent the oil from becoming acidic and detergent/dispersant additives to suspend particles for filter capture), boron, molybdenum, barium (usually used as a detergent in gear oil and not commonly found in crankcase oil), phosphorous and zinc (ZDDP anti-wear agents). Note: One can look at the phosphorous number and fairly accurately determine the ZDDP level in the oil. It is interesting to note that while the additives may undergo chemical changes during the life of the oil in the engine, they generally do not ‘go away’. They can still be detected in the analysis and reveal the makeup of the oil.

 

[Barko1]

Just my opinions, based on thirty five years of working around farm machinery and industrial equipment...[/i
Oil doesn't just wear out from heat (friction), it gets dirty.

I would beg to disagree From what I have read oil does "wear out" in the the viscosity declines and the decline can be significant and perhaps the best reason for using a synthetic. I really don't want to throw 15 qts of synthetic into my 7.3 so I'll try to change it by 5000 miles. Loss of viscosity isn't a good thing.

Here is a piece of one article on this subject. Motorcycle Consumer News did several articles and tests of different oils, dino and synthetic. I will always put synthetic in a motor that can run hot, ie aircooled.

What this all means in layman's terms then, is that the ratio established for each oil at the end of each test is a percentage of the amount of original viscosity retained at that point. For example. the Castol GTX sample at 800 miles showed a relative viscosity of 0.722, meaning it had retained 72.2 percent of its original viscosity. Or, if you want to look at it the other way, the Castrol had lost 27.8 percent of its viscosity after 800 miles of use in the motorcycle.

Just for comparison sake, I also tested the viscosity drop of the Castrol GTX automotive oil after use in a 1987 Honda Accord automobile. At 3600 miles of use, the Castrol GTX showed a relative viscosity of 91.8 percent.

As the Mobil 1 had retained so much of its viscosity after the 1500 mile test, it was the only oil I allowed to run longer in the motorcycle. After 2500 miles, the Mobil 1 recorded a relative viscosity of 79.1 percent.

Also, it is worthy of note that from a testing standpoint, the two most similar oils were the Castrol GTX automotive oil and the Spectro 4 motorcycle oil. By similar, I mean that they tested as having almost the same absolute kinematic viscosity and density right out of the container. So starting out as equals, the Castrol maintained its viscosity several percentage points higher than the Spectro, under the same use in the same motorcycle yet the Spectro costs about four times the price of the Castrol.

 

[Mark W. Ingalls]

While I believe your quote shows I said oil wears out from heat and contamination you are also correct, Barko, that its viscosity declines over time. I always thought it was primarily due to dilution from unburnt gasoline. Oil lasts longer in CNG and LPG fueled engines because of less dilution and less contamination.

Here is another interesting website on the topic: Motor Oil Myths and Facts