What's this on my Cylinder Wall?

[Realmongo]

After a compression check, I had one cylinder that was way low. So I just pulled the heads and noticed at the bottom of that cylinder there is what looks like a form of corrosion that has the appearance of what metal looks like when eaten by an acid. The section of the piston that was adjacent to the that section of the wall was covered with a whitish film that readily wiped off to leave a clean piston surface under that section that was covered by the film.

 

[vristang]

I am having a hard time orienting myself to the pic you posted, so I may be way off base.

Has the motor been sitting for a while, or was it sitting for any duration of time? It sounds like rust formed on the cyl. Maybe a HG leak let a little water into the chamber where it corroded the bore.

Is the corrosion in contact with the rings, or just the piston walls?

That is all I can think of right now.

jason

 

[RMODEL65]

I am having a hard time orienting myself to the pic you posted, so I may be way off base.

Has the motor been sitting for a while, or was it sitting for any duration of time? It sounds like rust formed on the cyl. Maybe a HG leak let a little water into the chamber where it corroded the bore.

Is the corrosion in contact with the rings, or just the piston walls?

That is all I can think of right now.

jason

i read these thing sometimes!

 

[Maryland Stang]

I agree, it looks like it was sitting with a HG leak.

 

[Realmongo]

I am having a hard time orienting myself to the pic you posted, so I may be way off base.

Has the motor been sitting for a while, or was it sitting for any duration of time? It sounds like rust formed on the cyl. Maybe a HG leak let a little water into the chamber where it corroded the bore.

Is the corrosion in contact with the rings, or just the piston walls?

That is all I can think of right now.

jason

When I boiught the car, I think it had been sitting for a long time. If it did have water sitting in that cylinder, that would explain the perfectly straight edge of the film on the piston.