QUESTION: Wondering if it's possible to "suck" water into the oil pan via an open exhaust valve while pumping oil out through the dipstick?<br /><br />ENGINE: '98 Mercriuser 4.3L Vortec with 53 pampared hours.<br /><br />BACKGROUND: <br />1)Changed the oil in my 4.3L with a factory Mercruiser manual oil changing pump, that screws on to the oil dip stick housing. Warmed it up to 160 degrees (~ several minutes), easily (not hard to pump) removed the ~5 quarts and changed the oil filter. No water in the oil, not even really dirty (but hey I'm religious about this stuff).<br /><br />2) Added 5 quarts, and checked the dip stick, and about 1/8" shy of full. Kept adding a portion of the 6th quart, and ended up getting too full (1/8" over full mark - but hey no water in the oil)!<br /><br />3) Next morning, ran the motor to warm up temp, re-checked the level (still over obviously, but still no water indicated in oil from the dip stick - still very clean looking).<br /><br />4)Connected up the manual pump out, and tryed to pump out. Noticed it was really hard to pull, and there was a "suction" on the pump that pulled the pump handle back down. I continued to pull with great force to pump out the oil, and now it's starting to look milky!<br /><br />5) After basically freaking out, I drained all the oil (which is definetly looking like Nestle's Chocolate Milk), replaced the filter for a second time, and re-filled with 5 quarts of fresh oil! Ran the motor for 10 minutes, from idle to 3000 RPMs, re-checked the oil via the dipstick, and it's clean again - no signs of water!!!
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