Bobcat T-590 Temp gauge trouble

[jcribb04]

I've got a problem that is wrecking our brains.

We've got a bobcat t590 skid steer. No matter what throttle you run it at the temp gauge fluctuates and throws a M0811 code. If you idle all the way down it will back the temp gauge back down to less than half. When you give it throttle back no matter if it's half or full it will fluctuate back to hot as soon as you hit the sticks and put it under load. If we turn it off for 2-3 hours we can get back in it and it will immediately start doing the same thing. Any suggestions on where the problem could be? We were thinking about putting a new Temp sender on it. Bobcat can't seem to fix the problem. They've put 2 new hydraulic pumps on it saying that was the problem and a new radiator and it still hasn't fixed the problem. Thanks in advance.

 

[brdgbldr]

Bad thermostat?

 

[foton]

I would spend a few bucks and buy yourself one of those hand held infered temp gauges with laser pointer . You can pin point anywhere in the engine bay and see the temps. you will be able to tell what is hot and exactly where it is hot at. and I would start at termostat housing, and temp sensor area, upper and lower parts of the radiator to verify they are working correctly or not.