I'm not panicing ... yet.

It's coming from the lower part of the motor ... not a knock, just a rattling sound, kind of like a playing card in a bicycle spoke but more metaillic.

I installed a Fluiddampr brand dampner and verified it's for a 96 motor. I do have a few questions about installation of the dampner, though ...

Checked for tie wraps, hose clamps, wire looms ... in all the pulleys. All clear.

The alternator and power steering pump are also known good units.

Replaced the tensioner with a known good tensioner ... no change in sound.

However, when filling with water and the bleed screw opened up, the stream of water weeped it's way onto the belt and it silenced it.

I plan on removing the belt altogether and see if the sound goes away. That would tell me if it's in the belt drive setup.

If it is, I will exchange the AC delete pulley with a known good one. I will also change out the belt as it's a used one I had laying around. The new one I bought for the motor didn't take into account the new dampner was 10% underdrive and not the 20% underdraive on my old motor.

Questions about the dampner ...

Is there a shim or washer between the dampner snout and the lower timing gear?

Is the CPS reluctor wheel an interference fit between the dampner and lower timing gear or is it bolted in some way?

I used the torque setting for the stock snout (74 ft/lbs) for this dampner. I never did feel it "bottom out", though. Should there be more torque on the ARP bolt I'm using?

As you can probably tell from these questions, my concern is I haven't snugged the dampner down tight enough and is allowing a shim/washer/reluctor wheel to rattle around between the dampner snout and the timing gear.

But I didn't assemble the motor, so I really don't know.

 

Great idea.

Not on a stock set up.

Sorry, mine is a 95 without the CKP. Someone will chime in.

Mine didn't bottom out either. Just use the ARP spec. Sometimes they request a bolt moly lubricant for some bolts but you'll have to consult ARP for the specs.

 

The reluctor ring fits on the crank keyway. The 96 and 97 LT1 have a longer keyway to accomodate it, and a shorter crank hub. First, I would take off the belt and spin all your pulleys, see if any make a grinding. If they do, the bearing is going out. Next, clean all the pulley grooves with an old toothbrush or something. They can be noisy if dirty. In order to fully seat the crank hub, you need a special installer. Use the search feature, a few members on here have posted about it. Then torque the bolt to spec. With the hub off, you might be able to shine a flashlight into the timing cover and verify the reluctor ring is seated on the keyway. But I doubt it is.

 

Thanks for the feedback ...

It was suggested to remove the CPS and take a peak inside as well..

 

Belt off ... noise gone.
New belt on ... noise gone.

I looked the old belt over and saw zero signs that would indicate this noise.
Weird ...

Maybe it was the aliens. They've been spotted just a few miles from here.