Hello All! Newbie here to the Pacifica forum. I recently purchased a 2008 Touring from my company. It was a traveling salesman's vehicle which has 237K miles on it. It has had religious oil changes and maintenance performed. Other than the odometer reading, you can hardly tell it was driven. It runs and drives smooth as butter.

I am hearing a "spinning-bearing-loose-rattle" type of noise only for a second or two on a cold startup. It goes away almost instantly. It is so quick I just can't pinpoint the origin. The pitch of it follows the engine RPMs...quickly goes up high then you can hear it go down just a little bit before it disappears.

I truly appreciate any input to this!

 

That is the noise typical of Main Bearings if only at start up. A heavier oil may help. I had a similar issue with a 3.5. While bearings did measure within spec, new bearings were .0005 tighter and the noise is now gone.
Chrysler 300M Enthusiasts Club ? View topic - 3.5 Engine Main Bearing Information/Analysis