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Misfire and possible chipped piston?

acidcrashdburnd

acidcrashdburnd

New member
After having detonation in cyl4 (13* KR) and bending a spark plug, I have changed my plug and wire, swapped injectors and coil packs and I still have a misfire on cyl4. I have a tapping coming from the top end that goes away once the engine is warm too. I have ordered new lifters and will probably do a compression test Sunday or Monday. I am thinking bent push rod, ****ed up lifter arm, or chipped piston. It idles fine and only starts to miss under load.

Lets discuss. I have searched the forum for chipped piston symptoms, its how I came to this idea
 


Wow, why do you have so much knock?

I bet it's a chipped piston at least, the bent plug is a dead give away. Happened to me like 3 years ago. Once I finally replaced my motor I found 2 chipped pistons, she still ran so smooth like nothing was wrong.
 
Sandman said:
Wow, why do you have so much knock?

I bet it's a chipped piston at least, the bent plug is a dead give away. Happened to me like 3 years ago. Once I finally replaced my motor I found 2 chipped pistons, she still ran so smooth like nothing was wrong.
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My car never normally sees more then 1-3* this time THE ONE TIME i drive it hard in months POP. I will just replace the piston(s) and hope for the best
 


go to google and look up home made inspection cameras, they cost about 45 bucks to make so they say.

then you can take a peek inside and see the piston.
 
Sure sounds like a chipped slug, it only takes a few seconds to pop one. A compression test should tell you what you need to know here. Mine was a small 3/4" piece off of #3 and the compression was 85 on 3 vs 155 on a good hole.
 


So the used spark plug I put in my car had a crack, it was changed and the misfire went away. We did a compression test that came back good on #4 and #1 and the tapping is still there. Going to change the lifters when i do the cam and hope for the best. I plan to still lift the head off to check valves and other things.
 
Mine had 2 plugs missing the ends but after changing them still had a tick. I live with it until the motor swap.
 
hi everyone im new here but i have a few questions i have a 99 gtp with a few small mods i recently swapped a 3.4 pulley and shortly after that i was getting KR but as the whether got colder it went away so i just put a 180 thermostat in yesterday so it would run cooler but right after i did it sputters when i go full throttle(WOT) or after it hits 4 psi i should also mention that when i did the thermostat i pulled one of the plugs to see if i should replace them but did not
 


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