Smoke, steam?, and an oily smell

[Guest]

I noticed last week that there is a smoky vapor eminating from the aft end of my exhaust manifold. I cannot locate the exact source; it comes out not under pressure but drifts upward from under or between manifold and engine block. The motor itself runs fine though I seem to have an intermittent sticky valve. I do not think this is exhaust gas; it does not have that smell and it does not set off the CO detector.

Of note (maybe), I have recently been using the practice of flushing my block with fresh water (I have raw water cooling in salt water environment). I shut down the intake seacock, wait for the temp gauge to hit ~150, then I open a fresh water feed. I do this cycle 3 or 4 times until I'm sure the water inside the block has been replaced with fresh water.

My question- what might the trouble be and is this a sign of an impending catastrophe? I sincerely hope not because vacation and a cruise are on the agenda very soon. The engine is (very) late model in a Tartan 34.

Many thanks for any replies!!

K Sturmann

[luvmyi36]

I will take a stab at part of it anyway... If you are doing a flush with fresh water, great! I think part of the problem, if I read your post correctly, is that you are keeping water out of the motor until it heats up. While the block temp is only 150, the exhaust is much hotter. If your setup is like mine, you may be cooking your hoses. I would recommend that if you flush, keep water moving through the system at all times. It may take a little longer to get warmed up, but you will not cook your hoses. HTH...