Have you ever worn out an engine?

4x4ord wrote:
I read recommendations made about the value in changing oil. I have been operating roughly 20 diesel engines at a time over the last 30 years. Some are 40 years old and still running. I have a Cat C15 that is approaching 1 million miles that has never been touched and runs like new. Some of these engines go years without getting an oil change. Over the years I have had one GM 6.5 Turbo diesel fail on account of the poor design which did not allow for proper cooling to the heads which in turn caused the heads to crack and pistons to melt; one Cummins 14 liter fail due to a valve dropping into a cylinder and destroying the entire engine; a second Cummins 14 liter fail when a coolant line broke and it overheated. But I have never seen an engine wear out. Is there anyone on here who has actually owned a diesel engine long enough to wear it out? If so, do you really think more frequent oil changes would have have prolonged its life?

The 7.2 Cat in my work truck is pretty much worn out...it has 15psi oil pressure at idle, ~35 at 2000RPM, and has lost a bunch of compression. (It has ~180,000 miles.) Seen a couple 7.3 PSD's lose compression...still ran fine, but were a bear to start cold. Most had 175-250K miles and 18-20,000 hours. (One had 29,000+ hours!)

Saw a 6BT Cummins that was worn out...but that was in an FL60 box truck with over 500,000 hard miles. It still ran, but wouldn't start below ~50 degrees and smoked under any load.