Caught failing rod bearings early, crank is untouched - lucky?

[ziggo0]

As my adventure had gone today in another thread, I was developing an odd tick or knock type sound. The sound was not occuring at idle and was loud enough to hear throughout the rpm band sorta like lifter tick. I shrugged it off because I figured it was due to light weight oil (just gone done with break in). Turns out due to Permatex not setting I lost quite a bit of oil, 1/2 to 2/3rds of it. The sound came up due to low oil. I wanted to shrug this off but it did not sound like lifter tick.

So I dropped the oil pan to replace the seal with something that would last and decided to pull a rod cap...the bearing was looking worn for being so young. I pulled the one next to it (2 & 3) and it was spun...or starting to spin. Please note during this time of knocking sound I had oil pressure, it was a bit lower than usual and would raise with the r's (only went to 3k and tried to keep it low the whole time hearing this). This upset my night. I pulled 1 & 4, 1 looked ok'ish and 4 looked as if it was on it's way out as well, when the cap was pulled and bearing dropped there was metal powder in it's oil. Basically oil starvation shot my rod bearings and probably didn't help the mains.

My question is, the crank surface appears to be...un-touched? I did the finger nail method of checking and not so much as a score on the surface. Checked with a mic and it's still machined down .25mm from stock. Did I catch this early enough to replace the bearings and knock on wood?

 

[joe sobo]

from my experience of trying to replace JUST the bearings will not yeild any good results. i have thought that the crank was still good too, and it spun them after about 10 miles of driving.

 

[donniekak]

The crank may be ok, but the rods that spun are shot for sure.

 

[TSIfreek]

Your best bet at this point is to pull the motor out and dissassemble it and check things over. If the rods have turned a blue color from a spun bearing they are junk.

 

[BogusSVO]

did you clean the crank when you picked it up from the machine shop? From grinding the journals, there is normally crud still in all the oil holes for the crank.

if there is any discoloration on the rods, they need to be resized/replaced as needed.