This month I was asked to determine the root cause of the catastrophic failures of several Cummins engines. My original report is in Spanish, and is the basis for my regular bulletin (#85) in Spanish the month.

Due to various requests, I decided to publish it in English as well, so here is the root cause analysis for those who are interested. It sheds light on errors in manuals, unjustified extension of oil change intervals, problems with used oil and used oil analysis, and a few suggested solutions.

As I say at the end of it, this should not be taken as an attack on any manufacturer or product. It is an open examination of the facts. It opens more Pandora boxes than it closes.


Maintenance Recommendations - Which are valid?

I hope someone finds it helpful.

Interesting. Especially the idea that procedures should be based on facts and experience, not hype.

Mr. Widman, thank you for taking time to translate your report. I have studied it as well as your Corvair writeup. Although my primary interest is motorcycles, I found a good deal of general information in both documents.

May I also extend my thanks to the owner of this site. It is the best source for technical lubrication information I have found. I have already learned a great deal and hope to continue to do so.

so shorter drains or use a 10/30 CI-4?

mean to say for winter use a 10/30?

Read that a while back. Excellent article. Just excellent.