RaZX6r

Hello All!!! It's been awhile since I've been on here so I just wanted to say what's up and if anyone can help me with a problem. Ok, since the last really nasty cold snap last week, my 04 grand cherokee has started overheating. It only does it after I've driven it (which it does NOT overheat while driving, or warming up in the morning). It seems to only start overheating when I get into a parking lot and sit there with it running. The temp spikes and a whine starts coming from the engine. Today it did it while sitting at a long red light. There's good heat in the cab and no water on the floors. Also after the whining noise starts, if I turn it off it sounds like the whine powers down if that makes sense. It doesn't stop immediately with the engine it winds down. From past experience from other older vehicles that overheating could be the fan, thermostat, or *gasp* water pump. So I'm wondering are there any sensors or anything I need to know about. Or is it one of the above things I mentioned. I thought it might be the fan not kicking in or something.... But please....PLEASE.... don't tell me it's a water pump.... Thanks guys!!!!

dave1123

If you have an electric fan, I would say the bearings are shot and the blades are vibrating and not getting up to speed. The whining is intriguing because I have a similar sound in my WJ that sounds like an aircraft gyro-horizon spinning down and there is nothing like that in a Jeep! The fan is permanent magnet and stops rather quickly. In other words, I haven't a clue!