Hello, looking for the recommended engine temperature operating range for 2.5L SOHC.

The motor was purchased - rebuilt - for a VW conversion, so I don't have the year and model of vehicle that the motor was originally installed in. Believe the motor is an EJ25 variant - EJ251, EJ252, EJ253 or EJ25W.

I suspect that installed motor is running cold, the electric radiator fan is almost always on, my analog temperature gauge doesn't tell me what temperature the motor is, though the gauge needle leans far to the left. Have an aftermarket ECU, I may need to reset temperature points in the ECU software so the radiator fan kicks in at a higher temperature, need to know what engine temperature operating range I should target.

My Haynes Repair Manual doesn't indicate the temperature operating range, nor have I had any success with Google searches. Thanks!