Eng Robert Bruce

My first guess would be left bank running lean...second cooling, possible obstruction in cooling line....Do you know the normal operating temp? is it possible the right bank is running cool rather than the left bank hot? If you have catalytic converter, the opposite could be true, to rich, or cylinder not firing on left bank....Is the engine itself hot, or just the exhaust?

The normal opp temp at working load is 900-950 dependi ng on load the cooler its self was reconed last week but the right bank is running about 50-60dgr lower than normal . no cat convertor

left bank is running at1080 right is 890

It seems at first glance that the coolant is accelerated on one side and restricted on the other, everything else being equal(?)...Is there any kind of t-stat control that may be malfunctioning? Do you have any pressure readout on the cooling line in/out? Does the same line feed both motors? Is there only one filter for both or two? Are any lines kinked?

No t stat control no lines kinked, no presure readout and its one line that feeds both sides, think u r right in saying that the right bank is running lame . it might b that a cylender os not firing in the right bank and ecm is making the left bank work harder.

Really lost here without a readout on the ECM....

Caterpillar Marine Power has online tech support. Don't know how much it costs.

ive been on the phone with cat finning aberdeen , i asked him if we could keep working (the last time one side went hotter than the other we dropped a valve) he said keep an eye on all temps and presures and he will send someone with the laptop but we r not due in untill monday.

Reduce speed and get there Tuesday? Maintain speed, something goes phut and get there Saturday?

I think it is miss firing in more than one last time the diferance was about 50deg and tell tell sighns . Exshaust shaking same this time but much higher temp