My Universal 32 hp diesel
in our 1983 Ericson
38 used to smoke white all the time. It was worse at higher RPM
. Revving the engine
would also spit out lots of soot as evidenced by the residue near the exhaust outlet. My guess is that it had 1800 hours on it when we bought it in the Chesapeake. We cruised the boat extensively for about 7 years putting another 3000 hours on it including charging
the batteries at anchor
I never was able to find anything wrong with it. I used synthetic oil
in it and had the oil
lab tested every 400 hours. Never turned up any issues. I replaced the heat exchanger
for a larger one it made no difference. I converted the water
pump to a higher capacity pump no difference. Raw water
exiting the exhaust seemed normal.
I had a 3 blade
feathering prop and I tried any number of different pitch
settings varying max rpm
from 2100 to 2900 but it seemed to run best when pitched to give about 2600 at full throttle. We typically ran it about 2000-2200 and made a nice 6 knots or so in flat water. Great reverse power with no walk but a friend with the same boat and original 2 blade
prop could get 7.5 knots out of his and run at 2700 rpm or so. He also smoked white ... more load, more smoke. Of course he prop walked quite a bit in reverse.
I had at least three diesel mechanics check it out over the years we owned it and none of them could find anything wrong with it either. I did have an infrared thermometer and periodically I'd use it to read the temp at the thermostat housing, the exhaust elbow
or the wet hose. It never read anything hot either.
Sorry I can't be any more help than that.