what would cause connecting rods and connecting rod bearings to be scratched

[posix]

with the engine out decided to taking engine apart to get a better understanding of how it status. leakdown numbers and compression numbers were good but with the engine out, decided to take it apart to be sure.

unfortunately there's scratches on the connecting rod bearings and connecting rods. any ideas what would cause this?

with this new info, definitely going to remove the pistons to see if there is wear.

 

[posix]

 

[HB Chris]

Get it mic’d and maybe polished and put in new bearings including mains, still pretty cheap.

 

[posix]

what does the term mic mean here? haha

 

[Bimmer 3.0 CS]

Micrometer

 

[boonies]

Get it mic’d and maybe polished and put in new bearings including mains, still pretty cheap.

Good advice...

To the question of how...oil starvation at some point?

 

[Stevehose]

Dirty oil?

 

[sfdon]

Looks like particle wear.
the answer would be in your filter.
hope you didn’t throw it away.

 

[sfdon]

http://www.isa1.net/isa/training/Bob_The_Oil_Guy_Bearing_Analysis_Chart.pdf

 

[tferrer]

Looks like particle wear.
the answer would be in your filter.
hope you didn’t throw it away.

As Don said. If you still have your old filter, cut it open and accordion it out on a clean surface with some good lighting. You don't want to see shiny dust...

 

[Gary Knox]

Looks like the engine had 'grit'. That's good in many situations, but NOT in the engine.

 

[posix]

Thanks everyone!

so if it is particle wear and I do find shiny stuff in the oil filter. Any common culprits of the origin of the particles?

 

[sfdon]

Oil analysis is your friend