Hello,I will be glad to try and assist you with this,Welcome to Just Answer.
Check your radiator and make sure the fins on the radiator and the front of the ac condensor arent bent or full of debris,if they are then you either have to striaghten them out or clean off the debris in order to get better airflow through the system.Also make sure the electric engine fans are coming on when the ac is on and when the temp gets warm,if they arent coming on then you could have a concern with the fans,computer or fan relays.Also in the hotter months or when running the ac it is ok for the temp gauge to climb higher as their is more heat built up and can cause this,most vehicles run a little hotter then normal in the hotter months and especially when at stand still/low speeds and with the ac system running in some cases,as long as its just a little past the halfway point you are ok,if it gets 3/4 of the way up then you may have a concern here.
There is less airflow when driving slow and when idling so the engine temp can get a little hotter then.
what engine is in this model is it the 3.8 liter series 2 engine or the 3.5 liter v6?
Let me know,Thanks Pete.
I dont have any pictures or diagrams of this engines thermostat replacement but I can direct you to a webiste that has this info,I hope this helped,let me know know if you need anything else.
A half hour ago I went to car.
The oil was 3/4 quarts low.
I did not add any oil.
Next I started car and it took about 10 minutes to reach the normal temperature.
At that time the fan turned-on.
But the temperature continued to go up to the 3/4 line.
I did not see anything unusual about the radiator.
Is this possible thermostat not openning problem? Note that if I drive the car the temperature goes back towards normal.
yes it is possible that the thermostat isnt opening up properly,this can be fairly common,also make sure the coolant is full,if the coolant is to low it can cause an overheat or hot running in idle or slow speeds and may cool down when driving.Either one of these could be your failure here,it sounds like the fan is working ok,it isnt a head gasket issue as the temp would continue to climb higher especially if driving faster speeds.