Hi, long story short...

I bought a new boat 26ft long 10ft wide 4 metric tons, full aluminum hull with integral aluminum cabin which houses the station and provides shelter for the Crew. It is a not a pleasure craft, it is used as a commercial craft for my small "rescue" and salvage company in middle europe on the freshwater lakes.
Why i got the D4: I bought the last boat used at the former jugoslavian coast for less than nothing and it had a penta KAD42P on it, and the engine worked flawlessly until the end. So I thought well the next one gets a new Penta.
The Problem:
Since the start the EVC keeps telling me that there is too less coolant in the circuit, which is BS cause I checked it numerous times and it is still on max. So I think it is just the sensor...
BUT, the bigger Problem is that i have to constantly (15hrs) change the diesel filters( one directly on the engine and one Vetus VTEB 34 as a prefilter in the fuel line), otherwise the engine will not start (4-5attempts) and on WOT it seems that the engine does not get enough fuel.
I have cut them open to examine and there is a greyish coating on them... I can provide footage.
Any ideas?

 

There are two flanges directly under the radiator cap on top of the engine. The glycol level must be above these otherwise you will get an alarm.