I bought a sea ray to fix up. It has a 4.3 mercruiser. Compression was 115 to 117 on all cylinders at cold temp. I have water in the oil and loosing power steering fluid with no leaks in power steering fluid. I do know one of the exhaust manifolds needs replaced. My next guess is the power steering cooler. Any suggestions, could I also have cracked block, should I just go ahead and replace the motor?