I think, something fell down one of the intake ports... pull the plugs and check for damage. pretty much have to pull the engine and tear it down...

 

It kind of sounds like my old motor when it broke a piston skirt. Not as loud though.

 

I had a lifter tick for a while, which ultimately resulted in a bent then broken pushrod. That resulted in a miss and kinda did sound like a minor knock. But you said you checked the valvetrain??? My solution was a cam swap and new valvetrain Well hey, goodluck. Keep us all informed.

 

Hey just saw the vid. Sounds a little deeper than the lifter tick I experienced, and louder too....but still pretty similar. Hmmmm....

 

Yeahh its weird, i just havent done **** to it. And im positive i didnt drop anything down there. I just wish someone knew what the hell that noise is haha.

 

well ill let u know tomorrow lol.. mine is making the same exact noise..sounds like almost from the same spot.. my mechanic will be taking a look ..

 

ok tight haha, my tuner is gonna come by tomorrow too cause he knows his stuff. But yeah def let me know whats up brotha.

 

does ur go up with ur rpms to ? mine does.. but its hard to hear over the exhaust sometimes

 

It might go up a little bit but idunno yeah cause the exhaust.

 

My advice is to stop running the motor untill you at least pull the heads and check for damage.

 

my mechanic/tuner came over tonight and unplugged one of the injector plugs and the backfiring stoppped. But the knocking he said is coming from a wrist pin? Thats what he thinks

 

Yep, time for a new rotating assembly.

 

might have a bent intake valve too causing the backfiring..

 

yeah true but i talked to my good friend who knows the cars inside out and he said he dont know how a stock vette can break a wrist pin unless lack of oil. And my car isnt a 1000hp car. He thinks its a lifter but the heads are coming off next week. And were putting new lifters in it.

Anything else we should check?

 

well considering how you dont know for sure whether its a wristpin or a lifter, maybe you should tear the engine down first before you start buying new parts....... Just my opinion but this could get kinda pricey

 

Did you pull that plug out and is it smashed?

 

I had similuar noise ....

check this threat.:
http://forums.corvetteforum.com/c5-t...the-motor.html


mine problem.....was that one piston was loose, the piston´s bolt went out to the sleaves walls.. and was rubbing against it up and down...

Godd luck man

 

Yeah that plug was pretty messed up, just all black.
It wasnt smashed like from something being in it.

And im not buying parts for it, my buddy has some lifters laying around his house, and if they fix the prob, then ill pay him etc.

 

OK, sorry it took so long
Took the heads off replaced my lifters with some comp ones, Got my friends ls6 heads that our milled down a bit, and some comp springs, new injectors plugs wires gaskets coil packs ect. ect.

Start her up and still a little knock, so i decided to just driver her around the block and the knock went away?

BUT its smoking a lot out the exhaust and under the hood, my mechanic said it shouldnt be smoking this much for that long cause something still isnt right. Still missin. P0300
HMMMMM?

 

Time for a proper tear down and rebuild.