Weird knock sound at idle only

[gpse3400]

My AIM is the same gpse3200.

[Jon89LE]

Lorenzo, if you see me online IM me. Any comments on the timing chain causing driveability issues?

[gpse3400]

Unless the chain is really loose. If that happen you'll notice a lag on the bottem end and more bias towards topend

[SappySE107]

I didnt hear anything when my chain stretched at 50k. The powerband definetly shifted higher on me but I couldn't hear anything nor did I know till I tore it apart to fix an oil pan gasket leak:P If you are using a cloyes chain, its probably stretched. I dunno if thats the cause of the sound or not but cloyes = junk in my book.

[Jon89LE]

Im not sure which chain my Machinist got for me but it has been shifting a little higher and hanging up there a bit more lately. Could anything in the middle/back of the motor cause a light sporatic knock? Loose rocker maybe?

[TheProfessor]

the timing chain wll start making noise way before you will have too big of drivability problems
and as far as the posibility of a loose rocker......i would say more probable that it is a lifter tick

[Jon89LE]

I guess its not a rocker/valvetrain issue then because its not that tick sound normally associated with that. The thing im confused about is i dont hear it on the front of the motor.

[TheProfessor]

maybe its the downpipe cracked
that happened on my retta and it made kinda a clanking noise

[Jon89LE]

Could an off-gapped plug make a sound like that? When all my plugs were loose the sound was very prevalent but once i tightened them up, it pretty much went away, but slightly remained.

[TheProfessor]

hmm not sure but i would say you might be on to something there

[Jon89LE]

Im starting to believe its a detenation sound im hearing. The way i see it, the excessive play in the plugs caused the gaps to change so even though most of the sound went away now, the gaps are still off causing some det at idle. I just dont understand how the motor ran a little over a tenth faster with the issue.

[TheProfessor]

id pull the plugs (one at a tiem of coase)
and check the gaps better yet just get new plugs and make sure you remember to gap them

[Jon89LE]

Well i ran Sunoco 93 through the car and the "knock" sound pretty much ran away. I was really on Empty when i filled her up so im going to give it a few days to get the 89 all out. So it looks like it was Detonation because the car feels a little better in the midrange.

Another question though. Anyone know what could cause all of my plugs to loosen up? I thought about the motor not being balanced but im using the FFP Pulley. Any thoughts?

[TheProfessor]

probably werent torqued down right to begin with