Can someone explain to me what happened to these pistons?

[DougsfastZ]

I know this isn't from a turbo Buick, but I figured you guys may know.

Got a 92 Accord with 230k miles on it when it started using alot of water. Cylinder number 2 and 3 were spitting water out of the spark plug hole when I tried to do a compression test. Pulled the head last night and didn't really find anything other then some damage to the piston number 2. It has a strange pitting/nicking on the front and rear of the piston in relation to the block. The head also has some similar marks in the same location. Here are the pics.

Rear of the piston.

Front of the piston, a bit less damage then the rear.

Sorry for the picture quality it was at night.

There is a bit of scoring on the number 2 cylinder wall.

Any ideas?

Doug D

 

[Cme2fly]

lack of octane= detonation

 

[TurboDave]

that looks like particulate damage. Something go through the engine??
Check the turbo's compressor blades, any missing?

 

[boostingbuick]

I agree. Foreign object.

 

[jhanson1750]

X3 on damage from something getting into the motor. (may be a broken ring)

 

[turbojd]

Looks similar to my piston when the spark plug electrode broke off and was chewing up the piston.

 

[DougsfastZ]

The spark plug stayed together. I was thinking possibly that the headgasket blew, causing water in the chamber, which cause the piston to "burn" and cause what your seeing.

Make sense?

Doug D

 

[granatl]

Is that from the engine that someone posted a few weeks ago where someone tried sand porting the heads with the engine running???

 

[1ARUNEM]

Ever seen cavitation in a pump (on the impeller)? This could be the result of the water being introduced into the cylinder. Heat brings it to vapor point (it won't combust) and hundreds of small implosions occur.

Just a guess..

 

[DougsfastZ]

Thanks guys. We are putting another junk yard motor in it this weekend. This one will be brought back as a core.

Doug D