I have a 2006 56 viking with 1500 mans the turbos are over heating and blowing because the angle of the engiens slant forward, so when you fill the fresh water expansion tank you get a air pocket in the turbos, because the turbos are higher than the water tank. is there anyone having the same problems that I am?? please help me!!!!
The turbo's on MAN's are not water cooled. They are lubricated and cooled by the engine oil. The expansion tank cannot be filled to the top on any engine or there would be no room for expansion (unless you have a coolant overflow bottle for it to go into), and the coolant usually sits 1-2" below the top of the tank. If you were low on coolant the engine water temperature would be too high long before anything else. This is not your problem. You're aftercoolers use water to cool them, and it is forced through with a pump driven off of the engine. If you are getting high turbo heat alarms, look to several different things. Is your bottom and running gear clean of barnacles and growth? Do your engine's reach the manufacturers stated top RPM? If the vessel is running too much propellor it will cause a high load/high exhaust heat situation. If both of these are in line, check and change both your primary and secondary fuel filters. BUT, from the year of the motor and sounds of this, aside from having a diver clean the bottom, CALL a MAN dealer and have a MAN mechanic come out and diagnose it.
No doubt the advice about calling a MAN dealer is the way to go here. The MAN engines I have seen have bleed screws on the turbo's for bleeding air out of them while filling in the expansion tank. This would lead me to believe they are water cooled.
you cant expect the owner of of the boat have to know where and how to bleed turbos when filling with water. it does not state that in the owners manuel
I am a little confused by your original post then. You stated that the turbos are overheating, and "blowing". How do you know they are overheating, and what happens when they "blow"? And if the turbos are no longer serviceable when "blown" who replaced them for you? Whoever knows enough wrenching to replace a turbo should know enough to bleed the cooling system when refilling? I have been reading up on the 1500 hp V-12, is this the one that came out right before the common rail motors and thus has 4 turbo's per engine, with sequential stage boost?
The 1500 hp MAn engine of that vintage is the D2842LE409 Two stage turbocharging with twin aftercoolers. Wow.