Does it sound like that all the time or just when cold?

 

It actually starts making the noise once it warms up. Sometimes it goes away after driving for a while. I'm baffled.

 

Bump

 

That stinks, I was thinking you may have the almost standard piston slap.

I am know engine mechanic but what I am seeing from others is if the noise starts or gets worse when it is warm it could be a possible bearing issue.

 

my buddy thinks it might be a loose wrist pin or broken piston skirt. the noise just doesn't seem loud enough to me. it's very quiet unless I have the microphone up against the block

 

I would point you to #6 rod bearing.
This is no exhaust leak. It is an internal motor noise.

 

Possibly a bad rocker. Get an automotive stethoscope and place it on the valve covers and see if there is a noise difference between the valvetrain.

 

I theory I could replace a rod bearing through the oil pan, right?

 

In theory yes you can. This will not be any easy task to make happen. Usually once you spin a bearing it does damage to either the crank or rod journal or both. You would have to have the damaged area polished so it doesn't hurt the next bearing you install. If to much polishing is needed you would then have to get a larger size bearing to make up the difference.

 

Thanks, I'm going to pull the pan soon and see what's going on.

 

When mine was making a similar noise cylinders 2,4,6,8 were all scuffed but the rod bearings were ok. It was time to get a stroker!

 

I wish I had the dough for a stroker and built trans.

 

Well over a year later and the noise never left. Recently it got much worse. I put on my buddies lift and discovered that the Flexplate was completely cracked in half. I have ordered a new one. Is there anything else I should while the transmission is out? I am amazed that it lasted this long.

 

the Flexplate was completely cracked in half. I am amazed that it lasted this long.

I'd say you got out cheap on this one! Bearing > flexplate

 

There's so many things you could fix/replace while the trans is out depending on your budget. But if your truck has higher miles at the minimum replace the starter. It's a pain otherwise and could save you a headache down the road.

 

I may do that. Rear main seal as well?

 

 

That's for sure. I was only out $60 instead of a new motor.