Squeak underneath.

05 with 10K miles. Wife says she hears a squeak now and then and on a previous older Marquis it was a broken motor mount. Anyone care to venture a gues what it coule be? Under warranty so I'll have them check it out, but you know how that goes, if they can't "reproduce" the squeak they can't fix it.

I think you probably need a new belt.
Both times I've had squeak underneath, I needed new belts, and luckily my mechanic wouldn't charge me.
Hopefully your promblem is similar to mine.

I presume you mean the serpentine belt because that's the only belt I know of. She said it did it for a week or so then quit and if it starts again we'll know where to look. Has about 10.6K on it now still under factory warranty so no skin off our nose but, as you know, they have to be able to "reproduce" the noise or they can't fix it. Might try some belt dressing and see if it stops and if not then get a Good Year Gator Back belt and put on and have done with it.

Thanks and have a super Sunday and better week ahead.

I don't drive hers that much but two and a half months later I finally heard it. On a relatively smooth road driving 20 MPH and definitely in the front sounds like it's a motor mount. Not really that loud, but loud enough to hear easy. Have to check with the dealer 'cause it's not the serpentine belt.