99 pc200 lc6 over heating issue

[Zachsea]

Hi all I’ve got a 99 komatsu pc200 that has got an over heating issue and I’m beginning to get stumped by it. The machine will operate for roughly 15 minutes gaining and loosing heat slowly and will ultimately get too hot to want to operate. Now if I let it idle for 5 or so minutes I get another 10-15 minutes of work out of it. So far I’ve checked the symptoms listed below as not the problem.

New radiator
Properly filled and mixed coolant/water
Fan is in good shape
Fan speed increases with rpms
No coolant leaks from hoses or pump

At this point theres only so many issues left to check and I know someone here has experienced this exact issue so anything at this point helps. Thanks!

 

[skyking1]

what about the thermostat?
Second is the impeller. I have seen impellers come off the shaft. The water pump does not leak.
Leave the cap off and look for flow across the top of the radiator.
I also use a heat gun to see where it builds up.

 

[Delmer]

Excavators are extra fun because the hydraulics can cause overheating even with the engine cooling system all in decent shape. Way too much going on to speculate, or maybe I'm just tired?

Use a non contact thermometer to take the temps of the top and bottom of radiator, or the outlet from the thermostat and the inlet to the water heater, and the block and head away from the exhaust. Also the hydraulic oil cooler. Take the temps when it is as hot as you get it, the temps won't show anything if the thermostat is partially closed, and is cool enough that it is supposed to be closed.

"will ultimately get too hot to want to operate", is this a hydraulic issue or engine coolant? what is it doing, blowing steam? alarm? slow/no hydraulics?

 

[Zachsea]

Excavators are extra fun because the hydraulics can cause overheating even with the engine cooling system all in decent shape. Way too much going on to speculate, or maybe I'm just tired?

Use a non contact thermometer to take the temps of the top and bottom of radiator, or the outlet from the thermostat and the inlet to the water heater, and the block and head away from the exhaust. Also the hydraulic oil cooler. Take the temps when it is as hot as you get it, the temps won't show anything if the thermostat is partially closed, and is cool enough that it is supposed to be closed.

"will ultimately get too hot to want to operate", is this a hydraulic issue or engine coolant? what is it doing, blowing steam? alarm? slow/no hydraulics?

That too hot statement means I myself dont feel comfortable running the machine at the temp the monitor displays. The machine doesn’t make any unusual noises but it does flash a low coolant light but the reservoir is full

 

[Delmer]

How hot is too hot, and what are you reading it with?

 

[Zachsea]

How hot is too hot, and what are you reading it with?

Only reading by the monitor on the machine. Too hot to me is 1 block away from being in the red.

 

[Zachsea]

As an update I did notice a decent leak coming from a cylinder so had it repacked. Now machines takes about an hour to get too hot but repeats the same process as before of taking a break to cool and reheating back up after 15 minutes.