8875 electronic display info

[gregsz2001]

Hello All, I just purchased a new to me 8875 skid, hour meter showed 1308 hours, judging by how pins and bushings are tight, steering levers and foot controls also tight, I believe hours are accurate. First issue I have is coolant temp rises until showing overheated. I check different areas of motor with infrared thermometer, not hot, I changed sensor yesterday. No change, I used the books tutorial for testing sensor, I cannot get display to show d. for diagnostic. I have put maybe an hour and a half on it just running around hour meter says 1319 hours, and other info seems off. Looking for ideas on how to proceed
TIA