I have a 2.0 LSJ Supercharged. Head has fully been rebuilt, Valves, springs, rockers, keepers all brand new, head gasket has been replaced along with exhaust manifold gasket and intake manifold gasket and supercharger gasket, also has been properly retimed with new cam gears, timing chain, and guides. When i came to start the car after putting it all together it took a while to start. After finally getting it started, there is a rough knock coming from the bottom of the engine. The knock gets faster the more the throttle is applied. A buddy of mine did a compression test and found that cylinder 3 has low compression. I got the oil pan off but i dont wanna just go digging blindly. Car will not stay running. Any suggestions on what this might be? Kind of a noob so dont judge me.

 

Gen 3 LSJ Short Block - Engine

 

Agreed, just buy this from ZZP and replace the lower end.

The sound is more than likely rod knock. Did you cycle the engine over to build oil pressure prior to turning it over after all the replacements?

 

Yea i did. But would just replacing pistons rods rod bearings and piston rings do it?

 

If the crank isn't screwed. But honestly it's going to be quicker and potentially cheaper (long run) to just pick up zzps or hit up MrB or Mongo if you're just staying with the M62 blower

 

I got the oil pan off. and the timing loose. i can't turn the crank. am i missing something?

 

Compression stroke. Take the plugs out, unless you seized a piston

 

I think i seized a piston, the head is completely off and the crank still won't turn. Car is not in gear. I dont know what to do now.

 

Can you see scoring on the cylinder walls?

 

Yes. But its not heavy scoring.

 

Do it once, do it right.

 

Pics

 

I found the problem. Cylinder three the rod was burnt and the rod bearing was torn up. When I can figure out how to add pics. I will.

 

 

Damn...

 

Holy oil starvation. How long did the block sit open?

 

only for about a day. But i found the problem. It was one of the piston oil squirters that broke off on cylinder 3 caused the rod to go bad and the bearing to mess up.

 

Holy ****. But oil squirters don't just "break off". Regardless revert back to post #2.

 

Qfe

 

that is not an lsj it is a gen3 ecotec

 

the oil squirter being broken off is not caused the rod bearing to fail as it has nothing to do with lubricating the rod bearing but what caused the oil squirter to break off was probably excessive bearing clearance allowing the piston to hit the squirter on the bdc transition

the purpose of the piston oil squirter is to cool the piston crown for cooler piston temps

 

SO because i spun a rod bearing what is the worst case scenario if i just swap the rod bearings, rods, piston rings, and the oil squirters and just put it all back together. without taking the crank to a shop?

 

you will need to replace crank and go gen2 piston squirters and rods

 

Who argued that it wasn't? Lol

Bang for the buck it's hard to beat for a replacement is all.

 

This is gonna sound like a stupid question but how do i start a new thread or new post? i can't figure it out.