What do you suggest as far as my next steps to diagnose or fix this? How can I tell if it is the radiator vs a fan problem vs something else? I will try out running the heater full blast and revving the engine in neutral at the stop on our way home tonight to keep the temps down in the meantime. As far as not driving it at all, we do need it up and running as our transport to and from work. We can use my wife's car in the interim but there are days when we have to drive separately.