its a 99 grand cherokee with the straight 6. it only happens when it is cold outside. has a whistling noise coming from the engine area for several minutes until the engine is warm...its very loud and you can hear it inside. it also goes away when you accelerate and its only there when its cold.

 

Doesnt sound serious

Probally just your engine warming up

was the car sitting for over a week in non use?

 

You just might want to check out the water pump.

 

Loose belt?

 

Heat rizer is leaking until it opens up !

 

i have a similar "problem' w/ my 98 cherokee
the serpentine belt is loose/needs adjusting

 

could be a belt or check your power steering fluid...