MIKER

I have a noise coming from the general area of the harmonic balancer. It's loud enough to easily hear it with the hood closed. At first I thought it was a bearing rattling on one of the accessories but after much investigation I have decided that none of them seem to be the source of the noise.
Adding to my suspicion is the fact that it is an old used 400 balancer and that the indicated timing settings are higher than they had been.

Any tips on how to verify that the rubber ring on the balancer is failing?
I suppose that I could find TDC on #1 and see where the timing mark lands.

PatsLs1vette

first check to see if is rubbing on the timing cover..thats your first clue then put it on tdc and see if the timing mark lines up..sometimes they do make noise when going bad if its rubbing.ive seen them wear right through the timing cover too.


[Modified by pats406nitrovette, 10:41 PM 7/28/2002]

terryrudy

When my balancer went, I could spin the balancer with my hand with the engine turned off. :eek: The whole rubber part just went on mine.
-terry

Woodstoc

This may not help now, but I saw a tip somewhere on scribing or painting a line across the balancer that will then show you if if slips in the future. Sounded like a good idea to me and I put one on everyone I pull off.

One way to tell would be to bring the #1 to TDC exactly with the dist. rotor pointing to #1, and see if your timing mark lines up.

Hershey

Also, you might want to just reach inside the front pully and see if the balancer bolt has backed out a little. Mine did this and had a good loud rattle that made me think all kinds of things could be coming apart. May be this simple or may be balancer as others have indicated. Hershey :chevy

Casper

The water pump was doing the rattle thing on my '82 . Drove me nuts till I found that what it was.

MIKER

I had a little time this afternoon so I again tried to find the noise. It sounds almost like a twig in a bicycle spoke.
I used a stethoscope to check all of the accessories. They all sound good.
I layed under the car with the engine running. The sound definitely sounds as if it's coming from the harmonic balancer (dampner). The rubber appears to be in-tact and it appears to be true (no wobble) and it's not rubbing on the timing cover. I verified the lower pulley assembly bolts were tight as well as the balancer bolt, all good.
Trying to pinpoint a sound like this can be very deceiving but I really think that I've narrowed it down due to the fact that I could put my ear within a couple of inches of be balancer while the engine idled.
Maybe it will get worse soon and I will find it one way or the other! :eek

Thanks for the tips. I'll let everyone know what it turns out to be when I find it.