Chrysler Repair: Whining noise, front wheel bearings, chrysler town and country

Question
hi Roland, I have a noise in my 2008 Chrysler Town and Country van that nobody can seem to fix. It's a whining noise that seems to increase and decrease with how fast the van is going. So far my mechanic has replaced both front wheel bearings, twice, he thought one was defective, the alternator and the air conditioner compressor. And the noise is still there. I'm starting to think that there may be something wrong with the engine or something but can't afford to spend any more on bad guesses at this point. I've read some of your previous posts and from the knowledge you have, I think you may be able to guide me to what needs to be fixed. Any help you can provide would be greatly appreciated. Thanx, Bill

Answer
Hi Bill,
The first thing would be to see if the whining is the same at a given speed, no matter if you are in 4th gear or 3rd gear. So listen on a level road when you can drive at a constant speed and notice whether the tone/intensity changes when you shift down (but at the same velocity) and then alternatively try driving at a constant rpm but in two adjacent gears (so the velocity will be different and note the difference if any in the noise. That will differentiate the engine/transmission from the balance of the drivetrain as the source.
Have you tried for fault codes: on-off-on-off-on and leave on in 5 seconds or less with the ignition key. Then watch the odometer window to see if the mileage reading changes to show any 4-digit numbers. Let me know if so.
Roland