This is a good one. Once it gets colder than 35 degrees outside, the car has a chattering squeal that starts at around 25 mph, and goes away after the vehicle is warmed up. I don't know how to find it, since it happens only when in motion. Definitely a "moving" drive train part. Any ideas?

 

usually squealing at low temps is caused by load on alternator, which can make the auxiliary belt slip or can be caused by alternator pulley/bearing or one of the bearings of components driven by the belt. Could also be water-pump?

 

Carznguitarz, the best option I see is to park the car on a level surface. You will then lift up the car and place it on 4 jack stands (one by each wheel). Ideally you want to keep the weight of the car on the suspension. So, careful placement of the jackstands is needed. Worst case, place it further away from the wheel if in doubt.

Once the car is up on the jackstands, start it, have a second person put the car in gear and take it up to the speed where the noise occurs and then you can walk along the sides and behind the car (never go in front of the car just in case it should happen to fall off the jackstands). From there, you should be able to narrow down the noise. You can even do this with the hood open incase the noise happens to be coming from the engine bay.

 

Possibly the rear drive shaft carrier bearing.

 

+1 on driveshaft carrier bearing. There's DIY info on how to grease it on this forum. That'd be the easy try; Plan B would be to replace the bearing, which is a lot more work.

 

Got rid of the wife....all of that kind of noise is gone!

 

+ 1 Larry, tried putting mine in the boot. Then came down with a terrible thumping at high speeds in the back. Finally sent her to Michigan now all is quiet while driving the beat up Nebraska roads.

 

iv had screaming noises dry belts was the problem, just gave it a good squirt from a wd40 can . but eventually changed the belts.

 

If the sound is pretty much between about 28-32mph, then it would be the carrier bearing. Do a search on here and you will see tons and tons of posts about that and most of them start in November/December as it starts getting colder in different places. It doesn't generally do it when the temperature is much above freezing.

 

Here is the correct answer.
The heat shield on the front cat is loose.
It is held with a nut/bolt which corrodes making the shield loose.
It only makes noise when winter arrives.
Its causing no damage... Just irritating.
Lay under the car.
Look up
Just above ur face will be a dimpled aluminum sheild about the size of a plate.
Jiggle it... I bet $100 its loose
(When under the car its roughly where the water pump sits)