TAMD 61A Engine Temperature Registering Low/white smoke

Hi All

I have one engine registering a lower than operating temperature than the other.
Is this more than likely to be due to a coolant sender issue ( rather than the coolant switch?)
Last year i had issues with a presure sender which had to be replaced on same engine.

On a side note i also have slightly persistant white smoke/vapour emitting from the exhausts and the turbo can be a little sticky from time to time when the boat has been sitting for periods.
Is their any remedy for this?

I'm not too concerned about the smoke issue , but if it is inter-related with a performance issue then i would be keen to address the problem.
The engine is 305hp engine with a max speed of about 17.5 -20 knotts on a good day-was advertised as 25 knots
I feel that it could do better , but its also an old fairline circa 20yrs old.

I could get an engineer friend to do compression tests and look at injectors but would be keen to exclude more simpler/obvious issues first.

And advice greatly appreciated

crawford alexander

Is the higher temp engine smoking, or the other way around??? what are exact temperatures, and at what RPM range?

One that is smoking:
- are you losing any coolant?
- is inside of the exhaust side of the turbo black from carbon deposits, or white (clean)?

General rule:
white smoke - coolant/moisture
blue smoke - oil
black smoke - fuel

oh boy yes,today big style, hole in floor of heat exchanger - perforaterd. Found remains of impeller partially obstructing heat exchanger :-( ...Also impeller knakered.
Therefore questions over the quality of cooling of the engine. And even bigger questions over at to why the temperature guage is reading lower than the starboard engine.
I suspect their is also a faulty coolant temperature sensor giving false readings. Struggling to work out whether the monitor or the sensor could be at fault. From the wiring diagrams i would suspect the sensor but i might be wrong...