I will admit that I would be guessing about what your pictures show here, but the main thing is, there is a leak. Question is where is it leaking. Thru a valve (intake or exhaust) or past the rings correct?
You did the compression test to confirms the leak, now do I leak down test to determine where it's leaking. There is a tool you cab buy to do the leak down test. It uses compressed air to locate the leak and what % is leaking. So if the leak is in the valves, pull the head, if it's the piston rings, pull the engine. If it were me I'd pull engine now. Much easier to work with it out of the car. Pulling the engine with one head out will be very unstable.
Good luck!
Thanks for your reply! I agree that pulling the engine with the heads still attached will make things easier on me.
I did do a leakdown test on the cylinder & found that it is leaking through the exhaust valve while at TDC. Now, I'm not sure if the imperfection on the cylinder wall would have an effect on the cylinder while it's at TDC, since it may be below the piston rings at that point.
Could I potentially line up the piston with the imperfection, and do a leakdown test at whatever position that is? I suppose I would be looking for air coming out *both* one of the valves & through the PCV. Or will that be too hard to trace down-- air coming through two places, a correctly open valve, and a potential ring leak?
I think your imperfection is a reflection off the top of you piston. It's the piston relief your seeing. Besides, the wall is very thin and I can't see how you could gouge the cylinder without packing in the drive train.
