Working on a low mileage 2001 A4 with about 35k on it.

Doing a harmonic balancer job for a friend.

Also trying to "find" a mysterious noise.
The noise sounds like regular LS1 chatter, just magnified.
And it only is "loud" at 1300 to 1700 RPMS..
Doesn't matter if cold, hot, etc.. Have done all the normal things
to diagnose... 2 oil changes, took off all belts, etc..
Noise is still there..
Oil pressure is totally normal for operating temps/rpms

When stethescoping engine when running: I can turn off each
injector one at a time with my scanner.. NO CHange..
Man those are loud with a stethoscope...

At valve covers, coil packs, exh manifolds.. all seems normal and
consistant from cylinder to cylinder.

So I got to bottom of engine.. And it seems like it's kind of
pronounced at bottom of timing chain cover area..

Let's Take A Look !!
Balancer, timing cover off... There is "slop" in timing chain.
something I would think i'd see on a 80K mile engine ???
But no smoking gun I guess...
I think while I'm here doing the balancer, I should do a timing chain set and oil pump..
THis is just a cruiser "old man" type ride, so stock type would be best
and I don't want to machine anything..
Found Melling Oil Pump: 10295 which is just a better quality pump over stock..
Timing: Melling 48560T9 which is Single Roller. I don't want to modify
anything to reinstall. And this block has NO provision for LS2 chain dampner.
So I don't want to drill block..

ANY SUGGESTIONS on noise issue or choice of parts ??
Thanks

 

I have valve covers off as well.. Nothing special in there..
Orange striped springs. All looks well.

I also took a video of the timing chain. I just don't know how to post it here
Its on my android type phone.

The noise sounds a bit like the usual c5 piston slap...
It just does it ALL the time under all conditions, but at 1300-1700 rpms ONLY

 

Can a timing chain or oil pump make "noise" at a certain rpm range ???
I've never experienced this symptom. ANY Help is Appreciated