Misfire and possible chipped piston?

[acidcrashdburnd]

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

[TEK310]

what the heck were you doing to get 13* of KR?

[acidcrashdburnd]

what the heck were you doing to get 13* of KR?

Going WOT

[TEK310]

what happened to your tune??

have you pulled your valve cover and looked?

[Sandman]

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.

[acidcrashdburnd]

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.

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

[Scottydoggs]

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.

[Seachicken]

USB Video Inspection Borescope Endoscope Pipe 7mm Waterproof Camera Snake Scope | eBay

[dsmuts]

Chipped piston. I told you

[acidcrashdburnd]

Picture of spark plug

https://sphotos-a.xx.fbcdn.net/hphot...30880940_n.jpg

[Anthony Smith]

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.

[acidcrashdburnd]

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.

[dsmuts]

Mine had 2 plugs missing the ends but after changing them still had a tick. I live with it until the motor swap.

[darkhorizon]

its a chipped piston.. Something had to close the gap of that plug, and I dont think the rod stretched.

[Japman502]

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

[dsmuts]

What other mods do you have?

[ItHurtz]

from chat he has cai, 3.4 and 180tsat on stock pcm THATS it. We all voted dead motor.

[dsmuts]

Some People

[Japman502]

Only mods are the pulley the stat after market boost gauge and flow master mufflers I runs to good to be blown

[Japman502]

And cold air intake