my 2001 grand caravan that idles fine in park and neutral but when i put it in gear it idles low and a loud noise comes from the engine. i just replaced the power steering pump 3 weeks ago. the noise was realy bad before that so i did need power steering pump. my next guess is the water pump. please help its our only reliable transportion and its going down hill.

 

Welcome to DF
I would clean the throttle body blades and ais motor first. Then take fan belt off see if the noise is gone.

 

don't i have an electric fan ?

 

Did you ever get a resolution to this? This is exactly how I would describe the behavior of our 2001 Grand Caravan Sport. Idles quietly in P/N, but as soon as it's put into D, it gets and sounds loud/rough.