02 Weird problem

[littlekpd]

HI, For the past couple days I have been working on my 2002 grand prix. I changed the oil seal. I had to remove the crank pulley. So I tore it all apart changed the seal and put it all back together. But when I fired it up I have a horrible knocking sound. just like a rod knocking. I have taken it all back apart again and made sure everything was where it should be and everything appers to be fine. but I still have this horrible knocking. I'm beating my head agaisnt the wall but that doesnt seem to help either. any ideas would be greatly appricated. thanks

[tblake]

You could have a bad harmonic balancer. The rubber on them seperates and causes a knocking sound just like a rod. Remove the serpentine belt and start it that way to see if the knocking sound changes.

[richtazz]

I agree with Tim, you may have a damaged balancer. The outer weight is connected to the center hub by a rubber ring. They can become separated, which allows the outer ring to move independently of the center section, causing a knock.

[littlekpd]

I did remove the serpentine belt and the sound never changed. I tore into the motor and removed the timming cover. the lower gear that holds the timming chain is cracked and hen it turns it opens. im not sure if this is the cause of my knocking but it certianly needs fixed.

[tblake]

That doesn't sound good. While you are in there it may not be a bad idea to replace the chair and tensioner also.