dnkynrbk

iTrader: (34)

Went out and tested my car after I had a nitrous backfire. I put new plugs in it. Took it out drove it around the block then open it up a little. Then I took it from a roll then I hammered it and spun thru first and it shifted to 2nd and then god awful noise started knocking sound like its comming from the valve train drivers side and thats where I melted the plug from. any help would be great.

dnkynrbk

iTrader: (34)

oil pressure is fine.

ss.slp.ls1

iTrader: (36)

Pop off the driver's side valve cover and take a peak.

Haans249

iTrader: (24)

It would probably be a better idea to just pull the head. Sounds like piston damage.

dnkynrbk

iTrader: (34)

pull the valve off and rockers and springs look good. so im guess im going to pull the head off this weekend

ss.slp.ls1

iTrader: (36)

Post pics, I hope it's not too bad.

ssmith512

Ouch. Hope it isnt too bad!

cam75w/ls1

iTrader: (2)

Dropped valve??

dnkynrbk

iTrader: (34)

pulled the head all looks good there is a small chunk out of the head and the piston as you see in the pics.
but all looks good. Any ideas. do you think is a rod bearing if so how can you check it. Or do you think its in the head and I should just go get the head checked? When the car was idling you could hardley here it but when you rev. it up it sounded like someone with a ball ping hammer hitting and it was comming from the head.

dnkynrbk

iTrader: (34)

SUCK MY SS

iTrader: (14)

rod knock is a pretty distinct sound...
it will also cause fluctuation in the oil pressure...
what lifters are in the car? do they have any obvious damage?

dnkynrbk

iTrader: (34)

the lifters all look good.

dnkynrbk

iTrader: (34)

comp oem replacement lifters

Haans249

iTrader: (24)

You're going to have to pull the piston to check the ringlands. Looks like there is some ring damage, but its hard to tell from the angle of the pic. Try looking down from the top around the piston. But, definitely need to pull the piston, and probably replace it.

LSmonster

iTrader: (2)

It looks like that "chunk", whatever it was, is what was causing the knocking noise... <(Smashing between the piston and the head)> If so, it could has pushed down the top of the piston, and now your ring could be pinching. <(Mashed ring groove)> from that chunk being there.

dnkynrbk

iTrader: (34)

ok got you when I had the nitrous backfire there were to hot cherrys I guess from the end of the plug. here is the vid v

dnkynrbk

iTrader: (34)

98Z28CobraKiller

iTrader: (17)

Rod bearing is wasted. I bet the rod is bent as well. The extra play on the rod is causing the piston to come up and out of the hole and is hitting the head. I just had mine rebuilt with similar damage.

SUCK MY SS

iTrader: (14)

this does happen...

but,i dont see any markings on the piston or head where contact may have been made, other than where the debris went through the cylinder..the quench pads will leave a pretty distinguishable mark on the piston top..whatever went through it was in an out quick...luckily for the OP...

i would still pressure check that head.. to make sure a valve seal hasnt been damaged...

i do think it is a rod bearing though...i just dont think its causing the piston to hit the head...

dnkynrbk

iTrader: (34)

going tom to have the head checked.