Mmmmm so my 300d 2.5 with 176k miles started to overheat at the beginning of the summer. I replaced a worn out fan clutch which fixed the issue for a few months. However now it's starting to run hot again, even worse if I run the a/c or drive hard. I have a thermostat to install however are the water pumps known for going out or the radiators for clogging? Car has no coolant leak. No other driveability issues runs great idle is perfect.