Chrysler Repair: 2001 300M overheating, radiator cooling fans, temp gauge

Question
70,000mi Dealer says radiator plugged up. Had a new radiator installed by dealer and replaced thermostat.

500 mi 2 months later, it is running hot again!

You suspect?

Answer
Hi Dennis,
Please describe the symptoms when it overheats: how soon after starting the car, under what driving/stopped in traffic conditions, what are indications of overheating, are the radiator cooling fans coming on when the temp gauge rises above normal, how does the temp gauge behave, have you lost coolant (from where if you can tell)? Also, has the radiator been properly filled using the special funnel so as to avoid trapped air, do you see any white smoke coming from the tail pipe when you start the car from cold, do you hear any boiling sounds in the engine during the warm phase, does the oil look normal, do the road wheels feel hot after normal driving? All that inforamation would be very helpful. It would be good to get a fault code readout to see if the powertrain controller has detected an abnormality. Autozone parts stores will do that for free or an independent shop will do it for about $40.
Please send a follow-up with more info and also mention which engine you have.
Roland