1996 Dodge 5.9L Cummins | T6 5w-40| 7,000 Miles

[madibob]

Blackstone comments: This is an unusual sample because chrome is fairly high, though everything else looks good. Chrome can show ring wear, though with a ring problem we'd expect to see signs of poor combustion like excessive soot and a thick viscosity. The lab did not note any soot in the oil, and the viscosity is right where it should be. Insolubles show solids in the oil, and those also often read high with combustion problems, though your insolubles are fine. Universal averages show typical wear for this type engine after 6,700 mi on the oil. The TBN is okay at 6.0. Try 7K miles again.

Miles on oil: 7,000
Miles on Unit: 64,970
Makeup oil: 0 qts

ALUMINUM - 4
CHROMIUM - 9 (FLAGGED)
IRON - 29
COPPER - 2
LEAD - 1
TIN - 0
MOLYBDENUM - 56
NICKEL - 1
MANGANESE - 1
SILVER - 0
TITANIUM - 0
POTASSIUM - 2
BORON - 46
SILICON - 4
SODIUM - 1
CALCIUM - 1442
MAGNESIUM - 1209
PHOSPHORUS - 1235
ZINC - 1459
BARIUM - 0

SUS Viscosity @ 210°F - 72.2
cSt Viscosity @ 100°C - 13.54
Flashpoint in °F - 420
Fuel % - Antifreeze % - 0
Water % - 0
Insolubles % - 0.2
TBN - 6

Oil was in for 6 months and I used a Mobil 1 oil filter. Any thoughts on the chromium?

 

[Donald]

Was the engine rebuilt? Its low mileage for a 1996.

You can see my posted UOA for a 1999 (same basic engine except for 24 v) with T6.

The chromium and iron are much lower in my post yet the mileage was longer. The silicon in yours is low, so no dirt getting in.

Not sure what to say, except you are running an excellent oil.

Here is some info (page 17) on chromium from the following URL:

http://www.ppmoiltesting.com/QnA.htm

Chromium in engines - rings, roller/taper bearings (some), liners, exhaust valves, wear treatment

 

[madibob]

The engine is original; the truck sat for 10 years until 2011, was run for a year (5K miles) and then I bought it at 58K miles.

 

[Donald]

Originally Posted By: madibob
The engine is original; the truck sat for 10 years until 2011, was run for a year (5K miles) and then I bought it at 58K miles.


When you say "sat" does that mean the engine was not started in 10 years, or it was not driven much in 10 years.

If indeed the engine was never started I could see rust forming inside the cylinders due to condensation, etc. That could be the reason for the iron being slightly high and chromium being high.

Compression test?

On the other hand, its a Cummins diesel. The truck will rust away before the engine is fully broken in.

 

[dnewton3]

Yes - if the engine truly sat stagnant for 10 years, that would explain the Cr and Fe. I'm going to presume that is the case here.

The rings will develop an affininty for that one position in the cylinder, and start to adhere over very long periods. In extreme cases, the rings can literally "stick" to the cylinders.

If this is the case, the Cr and Fe may settle down soon after that spot is worn in a bit. While flagged as abnormal (and it is statstically for the Cr), it's not obscenely high. I susepct it will pass and you'll be fine. It is, in fact, damage that cannot be undone without machining, but it's probably so small that it won't amount to anything and you'll still get many years of good service from the engine.

I would offer this consideration ...
If you plan to stick to "normal" OCIs, under 10k miles, then consider just using a conventional oil. You'll have less cost and similar results; wear protection will be fine, I can assure you. If you only intend one OCI per year, then perhaps a nod to the cold in MN might push you towards a 10w-30 dino or 10w-30 semi-syn like T5. Otherwise, if multiple OCIs are the plan, 15w-40 in summer and the thinner grade in winter.

 

[Donald]

So do we have an answer if the truck sat without being started for many years?

 

[madibob]

Originally Posted By: Donald
So do we have an answer if the truck sat without being started for many years?
Yes, the original owner passed away and the truck sat for around 10 years maybe slightly less per the family member I bought it from. He changed the oil right away and ran it for about 5K and it was due for an oil change when I bought it. I put in the T6 for winter and this OCI did have several very cold starts (single digits).

Originally Posted By: dnewton3
I would offer this consideration ...
If you plan to stick to "normal" OCIs, under 10k miles, then consider just using a conventional oil. You'll have less cost and similar results; wear protection will be fine, I can assure you. If you only intend one OCI per year, then perhaps a nod to the cold in MN might push you towards a 10w-30 dino or 10w-30 semi-syn like T5. Otherwise, if multiple OCIs are the plan, 15w-40 in summer and the thinner grade in winter.
I changed out the T6 for Mobil Delvac 15w-40 for the summer since I got a good deal on a 5 gallon pail. I plan to change to 5w-40 for the winters and 15w-40 for the summers.

 

[dnewton3]

That being the case, true stagnant storage for 10 years, the Fe and Cr is certainly a case of the rings sticking to the cylinders.

This will likely pass with the continued operation of the engine, and subsequent OCI/UOAs.

Nothing to fear here.

 

[LargeCarManX2]

Originally Posted By: dnewton3
That being the case, true stagnant storage for 10 years, the Fe and Cr is certainly a case of the rings sticking to the cylinders.

This will likely pass with the continued operation of the engine, and subsequent OCI/UOAs.

Nothing to fear here.


If rings ever stuck to cylinders, they would break right away when the engine turned over. Now if varnish and minor rust were present in the cylinder walls, the Fe and Cr could be the result of the rings scuffing off the rust and the wear of the rings doing it.

 

[dnewton3]

OK - game of semantics here ...

"stuck" or "sticking" was not well defined by me; sorry.

Anytime one metal has a chemical affinity for another metal, electrons of those metals will "swap" from host to alternate. The longer they sit adjacent, the more material exchange will take place. Depending upon the exact metals discussed, this can happen quickly or very slowly. There are times when similar metals can "marry" to each other with such bond that they may never come apart at that joint line without destructive force; this is why you NEVER store gage blocks together and MUST separate them before storage.

After 10 years of stitting completely stagnant, I can assure you there was direct ring/wall adhesion in this vehicle. While I agree the entire cylinder wall probably had some formation of rust (probably very light), it was that junction between the ring/wall that was in direct contact, and there was an exchange of free electrons, bonding the two materials at the molecular level.

Now, there clearly was not enough material exchange to overcome the starter motor torque, or it would not have cranked over and ran after 10 years. If that is how you define "stuck", then I'd agree they were not "stuck", because it was able to be freed.

But if you accept my definition, in that the were previously cojoined, but the starter was able to break them free, then my defintion would be correct.

Does not matter; the end result is that the material in the UOA is from the vehicle sitting for so long and being restarted. It is likely that as the now-renewed use continues, the metals will drop in the forthcoming UOAs.