Well, my water pump started sqeauling like a pig pretty bad, so I got a new one and went to put it in. While I was at it, I decided to remove the opti and do some cleaning up on it. I removed the balancer, removed the opti, took it apart and cleaned it up a bit, as well as the front cover. I put the opti back on and as I was putting the balancer back on, I noticed that the pulley section of it moved independently from the rest of it It had ALOT of play in it, you could spin it all the way around, as well as some forward and back play. So I guess Ill be picking one up tommorow. Im sure its been like that for a while, since I could feel it vibrate quite a bit when the A/C was on. It got me thinking, to all those that had a hesitation problem, would that be a contributing factor? Anybody else ever have a similar problem? You guys might wana check your balancers, pull the belt off and try spinning the pulley. Especial the higher mileage LT1s.

(97 Z28)

 

....... lt1's don't have harmonic balancers. crank pulley in front to driver accesories, and balanced out back.

and it should not be easy to spin the crank pulley. if it is, check compression. i am pretty big and think its pretty tough turn at times with a 1/2" ratchet. and for play if you are talking about the 3 pointed thing that holds the pulley on there, they have been known to be able to spin perfectly out of sync. check to make sure that bolt on there is tight.

 

Ooops, I meant pulley, just get used to calling them that.
But I prolly typed that worng, should of elaborated more.
When I took the pulley off again to inspect it, the ribbed pulley part of it would spin independently from the part that bolts on. It also moved back and forth.
Hope that makes more sense.

 

so the ribs off the crank pulley spin? in that case i am stumped. they are cast into it. are you sure you are not spinning the tensioner, powersteering pump, or the a/c comrpessor?

 

yeah, i think they are cast into it, therefor imposssible to spin.

 

The pulley section is connected to the ribbed section with a piece of rubber bonded to each of the sections. On a high mileage car it's probably shot, and will allow the pulley section to move or spin. Getting a new one, like you mentioned, will solve the problem.

 

You're quibbling over words here.... its a harmonic damper, and there is a rubber ring that connects the inner and outer halves. If that rubber ring is broken, it could lead to an increase in torsional vibrations in the crankshaft.

And he's not saying its easy to turn the entire assembly, he said the outer ring turns independent of the inner ring. The rubber isolator is torn, and the damper is now useless.

I'm not sure this would contribute to hesitation, although the resulting loss of alternator capacity as the pulley 'slips' would cause system voltage to drop, which could affect the injectors and the fuel pump if it drops low enough/long enough.

 

Yeah, that sums it up right there. Im gonna go pick one of today. One of my buddies I talked to said he had the same thing happen to him, after he replaced it, he noticed a slight hesitation from a stop was gone, so who knows. Ill let ya know what happens.
Thanks for the help

 

Well, I got er buttoned back up today. New crank pulley and everything, drove it for a couple hours and everything looks good. No leaks from the water pump or anything(knocks on wood). I can sure feel a difference Throttle response is significantly improved and feels smoother. The old water pump was on its last leg, when I got it off, it made a horrible grinding sound when I turned it. Im sure that was causing some false knock. Very happy with it so far.