Did a compression test today and when I removed my spark plugs 5 of 6 looked fine but one of the plugs was extremely corroded. Did some research and there isn't a lot of info on corroded spark plugs. In light of the compression test I believe I may need a new head gasket and/or piston rings. I overheated a couple times last year before finding and fixing my coolant leak. Any ideas as to how this thing got so jacked up? Could it have to do with my rough idle and sputtering acceleration when first driving from being parked?

 

I wonder if that's burned coolant or something.

 

Not sure that's "corrosion" but definitely some kind of buildup. Could be from coolant like IJM said. Could be stuff in the gas. No matter, it's bad and a bad sign. It could have certainly contributed to those issues.

What were your compression numbers?

 

Yeah so after some more digging it looks like possible oil buildup from a valve maybe? I think I've developed a lifter tick as well. I did a tune up and changed the cap, rotor, plugs and wires. The hesitation when starting the engine went away (my guess is the built up plug) and she starts well. The rough idle is still present. There's no more sputtering when first taking off down the road. I did a compression test yesterday but only had one spark plug removed at a time and reinstalled before checking the next cylinder. Also did it without open throttle. So I'll re-run a compression test today with with all of that fixed. Nonetheless, the results of yesterday's test were as follows.
1- 90 PSI
2- 130 PSI
3- 100 PSI
4- 120 PSI
5- 100 PSI
6- 130 PSI
Really hoping I don't have to tear into this head. I'm just now learning about engines and I have a trip in 2 weeks. I may have some long nights ahead of me. Wish me luck ladies n gents.

 

Take all the plugs out when you do this so the engine will spin easier. Also remove the fuel pump relay so the injectors don't fire.

You do need to do this at wide open throttle. Record the values.

Spec says 120-150 PSI with a max of 30psi variation.

If any cylinder is low, you can squirt a little oil (very little) and see if the number jumps. The oil will help seal the rings better. Too much oil will effectively raise the compression ratio. A big difference between "wet" and "dry" is a sign of worn rings.

Of course, the definitive test is a leak down test. This will tell you if any low compression is due to bad valves (or their seats), worn rings or a bad head gasket.

Was the "bad" plug in #1?

Good luck!!