I am new to the diesel world. My Cat 3116 E engines (1994 with about 400 hours) were serviced last Fall and had either new or cleaned heat exchangers as well as new impellers installed. While running my boat on a 5 hour trip yesterday the Port engine was 180 at 2200 Rpms while the Starboard was 190 degrees. Pretty constant at full throttle down to 1500 Rpm or so. The Starboard has the hot water tank while the Port has the furnace....if that even matters ?? My question is assuming they both have the same thermostats is this OK?? They were very smooth other than a rhythmic rumble at about 1600 rpm...not bad ....just noticeable. I did just replace the cutlass bearings as well.......My concern is whether the temps are within spec and normal.....thanks in advance for any info for a diesel novice !!
Do both engines meet their rated WOT RPMs? If I remember correctly, they should turn 2800 RPMs minumum at WOT. There should be no temp creep either for at least 5 minutes at WOT. I think 180 to 190 degrees running temp is fine for a 3116, but I would guess the temps should be closer port to stbd. If anything I would have guessed that the side with the hot water heater would be slightly cooler with the additional exchanger. Get a pyrometer and measure the actual temps on a few spots on the engine and compare side to side, they should be very close. Also measure gear and gear cooler. The temp gages are routinely off by several degrees.
It sounds normal to me for 3116's. I would think the differences also might be in your actual gauges due to their age. As the other poster said, measure water temp with an infrared.