Hi - My 1982 OMC 2.5L GM 4 CYL has had positive pressure in the valve cover. Open the oil fill cap and you feel puffs of air while it is running. I tested the compression and found 1st and 2nd CYL fine (130 psi). 3rd CYL. was low at 122 psi. 4th CYL was even lower at 97 psi. <br /> Question is this: Being a 21 yeal old 4CYL engine, should I just run the thing and live with a little oil consumption or will there be "unseen" damage that I should have the engine rebuilt now?