so my boat has been running great since I figured out the alternator issue. Checked oil yesterday just to see and couldn't get a reading so I added 3 quarts. Checked again today to see if had burned it all up after yesterday and the whole dipstick is covered in a grayish sludge. Does that mean my engine is cracked? I suspected at the beginning of the season because the freeze plugs were popped, but I had it checked and they couldn't detect any leaks and the oil looked fine after a few test runs.???

Light gray oil means that water has mixed with the oil. It is possible it is a very small leak, thus the delayed detection

The first thing you need to do is determine where the leak is. A little sludge on the stick is not a concern, but if the oil is milky then there is a problem. It will take a pressure test to determine if and hopefully where the leak is. Could just be an intake gasket leak, which is no biggie. <BR> <BR>Edit: pull the drain plug and see if water comes out. <BR> <BR>(Message edited by peter_c on September 11, 2007)

sorry to be ignorant, but what pressure am I testing? oil? leak down? compression?

Someone will need to close off the engine cooling system and put 14 psi of water pressure into the system closed up, then watch for a drop in pressure and for water leaking either into the engine or externally.