I have a 08 Pacifica AWD and when you are driving it sounds like when you were a kid and you put a card in the spokes of your bike. I thought it was the front passenger side axle but after changing it the noise was still there. I've had it up on a lift and ran it in gear and the noise wasn't as prominent as it is while driving it on the road. Any help would be appreciated and thank you in advance for your help!

 

Any chance it is as simple as the tire contacting the wheel well insert or other fairing?

 

I looked for signs of something rubbing like a shiny spot or something and there wasn't anything. Does anyone know what sound PTU makes when its going ?

 

I don't think the PTU is ever static. In other words it is always "going". I've never identified any particular sound with my car that I attributed to the PTU. When on the lift were you able to inspect all drive axles and the propeller shaft? Something wrapped around them etc? Just throwing stuff out. Hopefully our pro's will have an idea or two.

 

I did replace the passenger side front axle as I thought it was the culprit. It goes faster with the rpm's. I guess I didn't explain it in the best way, it does sound like an old Ford power steering pump that is low on fluid but not as loud. Thanks for your suggestions, sometimes the simple most obvious things are overlooked.

 

If you are dealing with a "Ford power steering pump" type howl or whine that varies with RPM, I would suspect the serpentine belt idler pulley or possibly tensioner/tensioner pulley.