3B Crank Journals Turned Blue?

[Gimme a 60]

Hey Mudders,

I took my 3B oil pan off to repalce the gasket. After removing the oil pan, I did a brief visual inspection of the bottom end and noticed a slight blue on the crank beside the the rod cap on a couple that I could see. Is this extreme heat normal for these motors at these locations? It has 320,000 km on it. The cam looks like it has normal wear. Before I pulled this motor I ran it for a few minutes and it sounded normal for a 3B motor.

See pictures below.

 

[SteveH]

You might ask in the diesel forum. I don't see how anything bathed in oil could get hot enough to turn blue. I wouldn't worry about it.

 

[LA Z]

The discoloration is caused by case hardening of the journal, witch is part of the manufacturing process.

See video below.
www.youtube.com/watch?v=pXVEW1ubiNM