1999 deville cooling system problem

my car ran hot most of the summer . the temp. here was between 105-116. i stoped useing it in august. i just started to use it this month and to car runs good no overheating. the temp here has been 40 - 60 deg.i changed the waterpump,belt,coolent ,thermostat,cap,hoses this summer. radiator was changed two years ago .any ideas on what the problem could be.....

my car ran hot most of the summer ...

What temps were you seeing and under what conditions? highway? in traffic?

What temps were you seeing and under what conditions? highway? in traffic? all street driving , car would overheat, or over flow tank would bubble up.gage would go to red zone,... thanks

Check the tension on the water pump belt. Sometimes the tensioner sticks and fails to maintain pressure keeping the belt tight.
Another possibility is a failed head gasket. Unfortunately, this is often seen, and for no apparent reason other than a design flaw, on the Northstar engines. There are test strips to check the coolant for combustion gas traces. You could also do a compression test to see which cylinder(s) if any fail to hold compression.

Check the tension on the water pump belt. Sometimes the tensioner sticks and fails to maintain pressure keeping the belt tight.
Another possibility is a failed head gasket. Unfortunately, this is often seen, and for no apparent reason other than a design flaw, on the Northstar engines. There are test strips to check the coolant for combustion gas traces. You could also do a compression test to see which cylinder(s) if any fail to hold compression. thanks for your help.....