3000 rpm metal tapping noise

[44pirate]

I searched for a few hours.
I don't get the tapping at idle only at around 3000 rpm to about 4000rpm. Under load it's louder. Free revving it is not as loud. From under the car it isn't as loud as it is from above the car.
Compression is 170 165 170 165. I pulled the VC and all the lifters are pumped up. I couldn't push any down. All the rockers look good.

I hate to have to pull the Oil pan.

Could it be the start of Rod knock a spun bearing starting to go?

 

[44pirate]

Pulled the oil pan. Found some copper brass shavings. Checked for CW it moves .1685mm. In my service manual it says 0.25mm is limit and standard value is 0.05-0.18mm.
#2 connecting rod cap wiggles a little the others do not.
I pulled the cap off sure enough one of bearings the hole is closed up.

So should I change all the bearings or just #2?

 

[rebuilt65]

It is probably too late. Once a rod bearing go's, you can't just replace it and it not fail again. (usually you can't). I heard that every once in a while, you can get lucky, but don't count on it. Try it, but change all of them, and don't get your hopes too high. I know, it sucks doesn't it?
regards.

 

[heavyD]

Originally posted by rebuilt65
It is probably too late. Once a rod bearing go's, you can't just replace it and it not fail again. (usually you can't). I heard that every once in a while, you can get lucky, but don't count on it. Try it, but change all of them, and don't get your hopes too high. I know, it sucks doesn't it?
regards.

Yep. Exactly what happened to my car and I am in the process of a complete rebuild.

 

[44pirate]

Originally posted by rebuilt65
It is probably too late. Once a rod bearing go's, you can't just replace it and it not fail again. (usually you can't). I heard that every once in a while, you can get lucky, but don't count on it. Try it, but change all of them, and don't get your hopes too high. I know, it sucks doesn't it?
regards.

I know. Just hoping to buy me a few more days. I have an eye on a 6bolt.

 

[44pirate]

Do you all know how much to torque the ARP Con Rod bolts?
Thanks George

 

[Defiant]

Check the harmonic balancer.

Or, just keep driving until it grenades.

 

[44pirate]

Well the crank is out of round so it's dead. 6bolt here I come.