Broke a piston, so took the engine out of my 2000 Cherokee to a shop to have it rebuilt. Got bored 30 over, crank polished, new pistons, cam, lifters, cam bearings, oil pump, etc (whole engine kit).
Had quite a time getting the pump to prime, finally got oil pressure and did the cam break in. Noticed oil pressure was low, builder thought maybe crank clearances were a little excessive so was going to order a HV pump. I pulled the pan to look at/change the pump and this is what I found.
So, what could have happened? It doesnt look like it spun, so the only thing I can think of is installer error. Has anyone seen this before, are there any tips/tricks so it doesnt happen again? This builder has 50 years of experience so I would think he knows what hes doing, but now Im not so sure.

 

Those look like chips left over from boring the cylinders to me.

 

Do they stick to a magnet?

 

Aluminum bearing material

 

"tips/tricks"?

Stay away from engine "rebuilders" that tell you a high volume oil pump is the solution to low oil pressure on a newly "rebuilt" engine.

 

There's no excuse for a mis installed cam bearing...He needs to make it right.. Clarify :" so it doesn't happen again". It's nothing you've done.....And the HV oil pump is a band aide for his mistakes...

 

I agree. He was recommended by a friend that has been a mechanic way longer than I have, and the few other people I talked to didnt have anything bad to say. I think at that point we both knew he had screwed something up but were hoping maybe he had just cut the crank a little too much or something, which if that was the case and the HV pump fixed it I would have been OK with it.

Hes gonna warranty it.

 

That cam bearing looks like it "walked" out

 

I thought about that as well...And if it did the cam journal is probably toast with the bearing...One scenario would be the cam bearing was cocked/too tight and it grabbed/spun...I always check the cam after installation to make sure it spins freely...Sometimes the install tool can create a burr.. In any case just imagine what the oil pump gears look like from grinding up those pieces...

 

Probably didnt align the cam bearing right. If you dont do it right, it gets no oil to the cam on that bearing which would cause it to spin and pop out like that.