I just bought this caterpillar 311. Serial num 5pk00323. Anyone can help on the year this was made. I've been looking everywhere... I also ran it for the first time today and it came close to being over heated, one dash from being in the red. It was very hot in south Louisiana but seems a little odd. I have rented equipment before and no problems. Equipment was very clean, including around the radiator, also radiator was full with coolant. Belts, including water pump belt, looked fine. Also seemed like it wouldnt have any strength in the low idling (1-3). Thanks for any help!!!!
Must be grey market? I don't see a 5PK 311 and that SN doesn't come up for me. As for overheating, most of the time the radiator is packed with crap in behind the Hyd cooler where you can't see it. And the low power at low idle, why are you running it like that to begin with. They are not really meant to be operated at less than full throttle. I'd be shocked if it did have any power throttled down.
5PK00323 is a Japanese-built machine from early-to-mid 1992. If the machine is new to you and as you describe everything such as coolant level, fan belts, etc, appears to be good I would suggest the following to get hold of an infra-red temp gun and shoot the temperature of the coolant hoses into and out of the radiator. Shoot the temperature of the block close by the thermostat housing as well. This will tell you if the thermostat is opening correctly and also if the radiator is cooling correctly. If you find a very small difference between coolant inlet and outlet temperature then the most likely cause is trash lodged in between the radiator and the oil cooler - a common problem. To clean this area will require the radiator to be removed.