I'm new to the forum but have been running a D6 310 in my commercial parasail boat for about 6 years.

Last season the temp started taking longer than usual to reach the operating temp of 185. When it did finally reach 185, it would only stay at 185 if I was running 2000 or more RPMs.

The local Volvo mechanic changed out the thermostat, which didn't remedy the problem. He remarked that the engine felt hotter than what the temp gauge was reading. He then changed out the temp sensor, this didn't remedy the problem either.

I asked if it could be that the gauge itself was bad. The mechanic seems to think that if it was a bad gauge it wouldn't work at all.

The computer isn't suppose to let the engine go over 1500 RPMs until it reaches operating temp(185), however since this problem has started I have been able to take the boat over 1500 RPMs after the temp gauge has dropped below 185.

My local mechanics seem to be stumped, has anyone run into this problem? Any suggestions would be greatly appreciated!

 

Hi all... !
Many reason are possible for this , recently i also faced the same problem and i found mud in my engine , you should must keep clean your engine .