no shaved head..
it's all still original from factory with 170,000 miles.
read somewheres that high compression could be result of carbon build up.
see i'm really wanting to put the lentech or valve body in my auto trans.
and checking engine health to justify putting more money into the car.
I don't have a leak tester. So did another test with the oil and compression went up to 200psi. in #1 and 2 cyl. stayed in the 190's for 3 and 4.
not sure if this means anything. being that the compression was already in the 180's Oh and I am glad I read somewhere to idle car for several minutes before driving to burn this oil out.
You are right about carbon build-up raising pressure.
The increase with oil is due to ring wear, but the amount of increase in 1 & 2 isn't so bad. You've got 170K miles.
I can't see the picture, but maybe you didn't post it yet? What color are they, best is a thin brownish coating for an older engine, thick black is oil burning.
Try running it fast with a tank of higher octane gas, and a bottle of combustion chamber cleaner, if you don't want to take the head off. But if you took the head off to clean it and regrind the valves, it would work better. Right now with regular gas, your ECM could be backing timing when you accelerate. That will leave more deposits, and eventually lead to cooking some number of exhaust valves, if it retards allot and you run it at high rpms allot.
Edit: The link appeared after I posted, it looks good.