2008 Chrysler Sebring NOISE

First is your vehicle still under warranty? Next, how many times has the vehicle been in for the same complaint? What are your states "lemon laws"? If your vehicle is still under warranty and the dealer cannot fix it you may be entitled to having the vehicle bought back by the manufacturer. In California the magic number is 3. If the dealer cannot fix a vehilce within 3 attempts for the same complaint then the owner has the right to have the car purchased back under the California Lemon Law. Not only do you get the value of the vehicle but all payments that hae been made are refunded. The problem will lie in if this is considered a "normal operating condition" or not. If Chrysler says this is the way all Sebrings are and it is a "normal operating condition" then pursueing a lemon law buy back may be more difficult.

I offered you this advice as an automotive professional. Many times in a forum format clients may not be aware of other options available to them and having your vehicle bought back is often times overlooked. I offered this advice because of the year of your vehicle and the fact that you had brought the vehicle in four times for the issue. Also please keep in mind this is a forum and most of the time a conversation must take place between the technician and the client in order to resolve the client's issue. With that being said, here as some possible failures that can be causing your particular issue.
A failing torque converter can begin to produce a howling noise in forward and reverse gears and in more extreme cases acceleration and deceleration.

A stuck valve in the velve body in the trans can create pressure and lubrication issues that often times will result in howling.

Also an extremely clogged trans filter can also create a similar issue however being that the vehicle is so new I would doubt this option.

I hope this was helpful.