to start off, this is not from an SS or even a cobalt..my buddies 04 Neon Srt-4 has a knocking noise coming from what seems like the head area..we already swapped rod bearings..and it didn't solve it.. when u turn the car on it cranks over and hits hard but at idle u don't hear it much..when u put it under a little load at 2,500 rpms u can hear the knocking very noticeably. Anyone have any ideas? we were pretty much banking on it being a bad rod bearing..but it didn't fix it..and he told me that if u put it right up to 5500 rpms it doesnt seem to do it...

I know this is SSnet but i know a lot of guys know srt 4s and motors in general so any ideas will be helpful

His mods are intake, Intercooler, boost controller, 3 inch exhaust, usually boostin around 16 to 18 pounds and we had a boost spiking problem but we swapped out the coil pack and spark plug wires so it smoothed it out then this knocking started.. dunno if its related but i figured id throw it out there

bump

piston slap maybe?

anyone?

 

maybe he floated a valve?

*shrugs*

 

i thought about that myself..would that make a knocking noise? ive never dealt with that before..maybe bent one

 

lol idk man.

never experienced it before either.

i'm just throwing things out there that i can think of.

 

thats what im goin for though.. just any brainstorming ideas.

anyone else??

crankshaft appeared to be ok also..

 

hmmmmmmm

my best bet is going to be its something in the valvetrain.

 

im kinda leanin towards that myself..im hopin to find someone whos experienced this or had to deal with it

i was thinkin maybe lifter..

 

Could his timing be off? Belt jump a notch.
I used to hang on those forums allot when I had my srt4....
learned allot over there....
But I haven't really heard anything on a problem such as this.

 

thats a possibility... i will look into that.. i never thought about that either

 

Possible valve sticking(bent maybe)
Do a listen with a mech stethescope or use a screw driver to your ear to pin point the origin and maybe do a quick compression test on that cylinder once you figure out where its coming from .The stick valve should show up if there is one.

He couldnt have the firing order wrong could he ?

 

possible crank bearing?

 

crank bearing looked good..gonna try the mech stethescope to pinpoint it.. im kinda leaning towards sticking valve myself.. i will update as soon as i can