my car's power fluctuates. its good sometimes, not so good others. i think i may have some scratches in my cylinders or my valves may not be sealing right.... Now if i did a compression and leak down test and they came out fine, would that mean that the cylinders and valves were fine?

 

You oil fouling spark plugs?

 

what?

 

a leak down test will tell you if everything is sealing properly a comp tester will tell you what your cylinder pressure looks like

 

.......so it will or wont show me what im trying to figure out. ( scratches in cylinders)

 

you can peep to see if your cyl walls are beat by doing a compression test, then squirting the low cylinder(s) with some motor oil. Redo the test and see what happens. If the # goes up dramatically, then you have a sealing problem with the cylinder wall. This can be deceiving soemtimes becuase the oil can mask a flat spot on the ring or broken ring/ ring land, however, a broken ring or ring land will a) make the exhaust give a "missing" sound, especially below operating temp and b) a cylinder with a broken ring land/ ring, if it does happen to recover PSI with the oil squirted, will usually lose the PSI easier during the next test vs. scratches in cyl walls cuz the scratches hold the oil from the squirt longer therefore put out good compression numbers longer.

How is the combustion? Do the plugs look even across the board and look like they are burning rite?