PLEASE HELP REALLY WIRED PROBLEM!!!!!!!!!!

[240sxRturbo]

smashed cylinder 4 spark plug .......slite taping is heard alos tapping sometimes turn into knock but then goes away and the it will return .........what causes this?????????????????????? thank you




ok so i was driving my fresh ka24de s13 and car dies cuz dizzy went bad replaced dizzy and now when i rev it up it sucks n air then revs up very weird.....so decided to take it for a test drive drove the car seemed to be doing ok besides missfire at lowrpm pulled into a drive way to back up and head back to the garage got stuck in driveway so had buddy push while i gave it gas and wasnt giving it to much but when we finnaly got out the car was making weird noises and was only firing on 3 cylinders so babied it home and pulled number 4 plug out it was smashed so i replaced that injector and plug and when i started it back up and it idled good but i was hearing a tapping noise that turned into a slight knock but then would go away so pulled plug again and the gap was closed btw this hole motor besides the crank is all brand new and yes crank was checked and it was fine so i removed my new bearing on the rod on that cylnder they look still brand new so i am at a loss i dont know what would cause this please help me i am pulling head tomorrow to see whats up in there

any idea would greatly be appriciated


broken vavle spring maybe ?????

i know the piston it self cannot hit the spark plug becuase of the way the bottom og the head is designed so it has to be something else

[breadbox]

so from reading this your #4 cylinder is destroying your plugs?

You had head and block decked?
And you have a HG of sufficient thickness?

[OutToWinPAHC]

Yeah something is off.... I wonder if that valves also kisses?

[240sxRturbo]

i am pulling the head off today i will take pics of the smashed spark plug and the under side of the head

[240sxRturbo]

so from reading this your #4 cylinder is destroying your plugs?

You had head and block decked?
And you have a HG of sufficient thickness?

thanks for trying to help me figure this out

yes i got it deacked

and if the HG was to skinny i would have more than just a cleanance issue in one cylinder

[DanThaMan]

could be just a piece of big garbage bouncin around in there from when it was put together. I've also seen valve seats come unseated and cause what you've described. That is very strange though, I look forward to what you find.
-danny