"Air Compressor High Air End Temperaure Problem"

In our plant, We used three air oil injected screw type air compressor of Ingersoll Rand (MH45) providing 8 bar pressure by each to the system.

But high air end temperature problem coming frequently. We have changed the associated valves, sensors. But still, after 12 hours of service from being started, the problem is still happening.

Is there any one having the same problem?? can any one suggest any corrective measure??