my o4 PAC makes a weird noise from front left (under driver's feet) when I brake and just right before it stops. I have been noticing this noise before I 've changed the brake pads and disks and also after. It is not the brakes. It sounds like a plastic part inside a metal or a metal part encicled with plastic is trying to move in a tight place(a sound like grrccth grccht)it is worse in cold weather.....

Please help...

 

It could be your engine cradle, a sway bar bushing or something in the suspension. Going to be hard to tell you without hearing it. Have someone look at it.

 

Your description of the sound reminds me of the classic Chrysler transmission solenoid sound. If you garage your car, pull it in, roll down your driver's window and listen as you shift from park to drive, park to reverse etc. I have become attuned to hearing it so much that I hear it in other Chrysler cars/vans as I walk through parking lots or am at a stop light with my windows down. I hear it in my own car as the tranny downshifts into 1st just as I stop.

 

I am told this is common with the pacifica and that there is a service bulletin out on it. mechanic told me no fix is necessary.

 

FIND A NEW MECHANIC.....

Google Chrysler Pacifica TSB# 03-002-06 and follow step by step....NO SHORTCUTS.....It works out very well if followed EXACTLY.....

Now ..Being an AWD....if the bulletin does not apply, or leads you to further diagnosis, The problem is likely in the PTU (Power Transfer Unit). Problems within PTU are not to be ignored,as they CAn easily and very quickly escalate into Transmission and driveline Catastrophic failure, or a severe loss of vehicle control.....MAking it BLATANTLY unsafe.
Mileage.....????? An 04 MAY still qualify for 7/70 POWERTRAIN WARRANTY if indeed a fault is found in the PTU...

For a mechanic to tell you NO FIX IS NECESSARY is playing Russian roulette while pointing the gun at YOU....