1999 Buick Park Avenue Engine running hot at idle

I'm not sure why it used to run cooler but this is acting pretty much normal.

It has a 195 thermostat and as long as the car is moving and forcing air through the radiator, it will run in that range, however when going slower it's programmed to run differently. The electric fans aren't programmed to come on until 212 for low fan speed. It has a second high fan speed that doesn't kick in until 226 degrees.

Here are the details from the service manual.

Power for the cooling fan motors comes from the Cool Fan 1 and Cool Fan 2 Maxi fuses (R).

During low speed operation, the PCM supplies a ground path for the Cool Fan 1 relay through the Low Speed Fans control circuit. This energizes the relay coil, closes the Fan 1 relay contacts, and supplies current to the primary cooling fan. The ground path for the primary cooling fan is through the series/parallel cooling fan relay (Cool Fan 2 Relay) and secondary cooling fan motor. The result is a series circuit with both tans running at low speed.

To command high speed cooling fan operation, the PCM first supplies a ground path for the low speed cooling fan (Cool Fan 1) relay through the Low Speed Fans Control circuit. After a 3 seconds delay, the PCM supplies a ground path for the series/parallel (Cool Fan 2 Relay) and the high speed cooling fan (Cool Fan #3) relays through the High Speed Fans Control circuit. During high speed operation, both the primary and the secondary cooling fans are supplied current through their respective maxifuse and each fan has its own ground.

IMPORTANT: When certain Diagnostic Trouble Codes (DTCs) are present, the PCM may command the cooling fans to run all the time. It is important to perform A Powertrain On Board Diagnostic (OBD) System Check prior to diagnosing the engine cooling fans.

The PCM will complete the ground path for cooling fan relay #1 under any of the following conditions:

* When engine coolant temperature exceeds 100 °C (212 °F).
* When A/C is requested and ambient temperature is greater than 4 °C (39 °F).
* When A/C refrigerant pressure is greater than 190 psi (2 volts).
* When the ignition is off and engine coolant temperature is greater than 140 °C (284 °F).

For high speed cooling fans operation, the PCM will delay control of the Cool Fan 2 Relay and Cool Fan #3 relay for 6 seconds. The 6 second delay ensures that the cooling fan electrical load will not exceed the capacity of the system.

The PCM will complete the ground paths for cooling fan relays Cool Fan #1, Cool Fan #2 Relay and Cool Fan #3 under any of the following conditions:

* When engine coolant temperature exceeds 108 °C (226 °F).
* When A/C refrigerant pressure is greater than 244 psi (2.5 volts).

Check the radiator if its clogged and also if the water pump doing its job if okay test the thermostat and also try bleeding the system and see what happens. If it continues have it block and pressure tested.

Simply cycling it from operating temperature to fully cool a couple times should bring all the air to the top

Be sure to check that coolant level when it's fully cold before it's driven.

If you read the explanation from the service manual, a temp as high as 225 can be normal if it's on the way down at the time. If it never goes any higher than that, then your fine.

No, don't open the system after it's been run. The coolant expands. You want to check it cold. If you have to add any, wait until it has been driven and cooled all the way down before checking it again.