ok i recently bought a 99 sunfire gt convertible with a 2.4 twin cam. i bought it with the impression that it had a rod or main knocking. the problem is it does not act like a normal rod or main knock because it is not always there and i know its is coming from the lower end. i have recently been educated on the balance shaft and i am thinking that is where my problem is. it does not change with rpm all the time and it does not matter if it is warm or cold on when it will do it. under a load it seems to do it more as a rhythm but it will become random when it returns to idle and sitting there revving it. it comes and goes. i have held it at 4500 rpm with no noise and no noise on snap revving but then if i let it sit and idle a few seconds and hit it it will knock so i am dumb founded........ my ASE certs have recently expired so i do have well known knowledge on mechanics but this is new ground for me and any new info is greatly appreciated. i like this site and i am glad to be a new member so any help is great thanks ed.

I would remove the belt and see if the noise goes away.


- 2004 Cavalier - 124k, owned since new

hmmm...... how would that help? i have never heard of that before... is the balance shafts somehow driven from the serpintine belt? i'm not critisizing in any way hope you don't take it that i am. just needing some more inforamation on what that would do to help narrow it down? thanks for helping me though i really apprieciate it rob