LS3 Valve Broken in Cylinder. Any Help!
 

I recently had problem on my LS3 it started with a really light ticking with a check engine light P0305 i did some research and saw these have lifter and valve issues. I bought 5602 morel lifters from TSP since i do push this car a bit more than usual driving. i also got a TSP Stage 4 Cam package while I was at it.. i drove the car for about a month and a half since i requested my vacation so i can open the motor and change the lifters... 1 DAY BEFORE VACATION!! THE LAST DAY!! My engine stated knocking and lost power drastically at 30 MPH... next day I opened the motor and the Cylinder 5 Intake Valve Broke.. My question is by the looks of it how bad is this damage... i turn the crank and the cylinder goes all the way up.. compared it to bank 1 cylinders and looks like its the same only the top is cut.. I'm replacing the head.. seems everyone is going to the 823 instead of the original 821.. Also bought a new piston from Graff Chevrolet for $94 since i dont wanna upgrade n do any big modds while im still paying the car off... Any help! Thanks!

Ouch, when you pull the piston check the rod and bearing and make sure there isn't any damage to them. Have the head checked for cracks, have a new valve seat installed and cut and a new guide and valve installed. Also clean up any burs or marks in the combustion chamber on the head. And make sure the shroud (?) over the spark plug hole is not damaged.

One other thought, when you pull the rod off check the crank over really good and check the front to back movement on the crank to make sure you didn't bend anything else. When you stop a piston like that it can cause damage to the heads and the bottom end of the motor. Post up some other pictures after you clean it up and before you put it back together. Good luck on your project.

Thanks! Im replacing the heads, this head is ****ed really. the only thing that worries me is my crank and rods. when im checking for this damages is it something noticeable or something that has to be checked with measuring tools??

Did it mess up the cylinder walls? I dont know how it couldn't have. I doubt it hurt the crank. You have to drop the pan to change the piston. When you pull the piston, take the rod to a machine shop and have it checked or just get a new one if cost is your conern. If that was mine the motor would get pulled and completely gone over.

Yea i pulled it out! and no luckily the Cylinder wall was not effected. when i was driving and heard the engine knock right away in 5 to 8 seconds i pressed on the clutch and turned off the engine and let it coast down the hill. lol.. also when i removed the Intake, part of the valve was in there. so i guess it all went back up to the intake n didn't stay in the cylinder for long... so kinda lucky n not lucky at the same time! but seems like a good idea ill get the rod checked and maybe go buy a new rod. ill call the dealer and see how much they are going for.. Thanks!

Wait.....do you seriously have oak parquet flooring in your garage, or did you roll the engine into the dining room? LOL

Totally sucks about the broken valve. How did that happen? Did you find the root cause?

:bellyroll:

You got that motor out quicker than a dealership! Good luck with your repair, sucks but looks like you know what your doing!:first:

All I see is the horrible wood flooring, the shitty yellow engine stand and the "Prince" Purple Rain background. WTF is going on here?

Lol yea i rolled it thru the dining room, its actually in my room. My roommate was like what the ****.... lol..

And i highly believe it was just the valve. A while ago i down shifted to first gear instead or 3rd gear. RPM went above 8500. And i was doing around 60mph! So yea not a fun situation lol

Thanks. The removal is super easy but putting it back together is another story. Lol so far i just bought the piston and rod along with new bearings. My damage wasnt to critical so spending 200 on that is better than a new rotation assembly any day!

Sorry bro i thought this was a car website not house remodeling station.. i rent here temporary really dont give a **** how da shit looks or stinks. And the purple is a black curtin just a sunny day outside seems to be normal when you apply light behind it. Ill check for a recall if that satisfies you?!. And If you like it. Walmart has them for like $4 on isle 340. And the shitty stand yes i know ive had it for about 6 years lucky it aint broke yet. I guess what ever works works type of deal. This is day 6 and its still standing. Totally worth the $20 i paid for it! Yeeessss!!

He'll yea you gotta to do what you gotta do. Hell I never even notice a curtain. Good luck with the build and give some updates.

lol you sure do. for now GM called me that the parts weren't delivered so just waiting on that. A friend of mine said the head can be fixed and just buy a new valve or upgrade valves since the factory hollow valve seemed to be a problem on LS3s. another things was to switch to 823 casting heads. same head just different valves. mine are 821 casting heads

Was it a ticking noise or a tapping noise when you shifted to the wrong gear. I did that the other day and it has a slight tapping noise on the driver side. Don't want to drive it if I'm going to **** it up. Wish I had a garage to take it apart