Latest oil report on my '98 Dodge 24valve Cummins.

Mobil Delvac 1 5W-40
In service 10/17/03, drained and sampled 8/24/04
Miles on engine: 111,366
Miles on oil: 17,134
Oil filter: Fleetguard StrataPore
Air filter: Amsoil oiled foam
2 oil filter changes throughout the course of the interval, about 2 quarts make-up added.

Lab: Cummins PowerCare DePere, WI
Aluminum 6
Chromium 8
Copper 13
Iron 27
Lead 5
Tin 9
Silicon 11
Potassium 34*
Sodium 38*

Water 0.3
Oxidation 6.6
Visc@100C 13.8
Glycol N/A
Fuel <2.0
TBN 8.4
Nitration <2.0
Soot 0.7

*ABNORMAL
Comments: All engine wear rates normal. Check for source of coolant leak. Drain oil and change filter if not already done. Resample at next service interval to monitor.

I'm suspecting the culprit for the coolant source may be the oil cooler. I have a sample sent to blackstone also, and will compare results. Cost of this lab report was $14.95 postage paid.

I have run 5% Bio-diesel fuel occasionally during the spring and summer. Otherwise I fill up with BP Amoco Premier 50 cetane diesel fuel. As of late, I've also been using Schaeffer's Soyshield additive, and Power Service in the past.

Comments welcome.

And here are the results from Blackstone Laboratories, which show a much better picture. The two samples were drawn back to back.

Blackstone/Cummins PowerCare

Aluminum 5/6
Chromium 3/8
Iron 26/27
Copper 3/13
Lead 3/5
Tin 1/5
Moly 1/-
Nickel 0/-
Manganese 1/-
Silver 0/-
Titanium 0/-
Potassium 3/34
Boron 32/-
Silicon 5/11
Sodium 3/38

Calcium 2888/-
Magnesium 475/-
Phosphorus 1195/-
Zinc 1451/-
Barium 0/-

SUS visc@ 210F 74.6/-
cST visc@ 100C -/13.8
Water 0/0.3
Antifreeze 0/N/A
Fuel <0.5/<2.0
Insolubles/soot 0.5/0.7
Oxidation -/6.6
Nitration -/<2.0
Flashpoint 450F/-
TBN 6.6/8.4

Sump capacity on this engine is 11 quarts. I'm sure glad I decided to go ahead and send a sample off to Blackstone in addition to one sent to the other lab. Otherwise, I'd definitely be in a quandry at this point.