I purchased a 2008 Subaru Tribeca about 6 months ago. Like many of you, I loved the car. Soon after getting the car I noticed a high pitched noise when the engine was warm and I was stepping on the gas pedal at about 65 mph. I brought the car to Delray Subaru in Delray Beach, Florida for service on this issue. After a number of visits, Dave Adams the Service Manager rode with me and verified the noise. It was most distinct at 2200 RPMs and 62 1/2 miles per hour. He said he would review it with Carmine the Subaru District Manager. I was told that Carmine and Dave test drove at least 3 other 2008 and 2009 Tribecas and found the same noise. I was told that the factory would evaluate the situation and find a solution. After two weeks of no responses, I called Dave Adams who had no information but assured me that Subaru was looking into the problem. I called Subaru of North America and was told they would look into it. Today I received a call from a Kevin Shumaker of Subaru who advised me that he confirmed there was an issue, but that Subaru had no intention of further investigating the noise. I asked him what caused the noise. He said they did not know.
The noise is quite loud as the engine gets hot. Yes, a radio could mask the noise. However, the radio is not appropriate all the time.
Before you buy a Tribeca, you might see if this noise bothers you as it does me. Maybe someone out there knows if the noise is a problem in the functioning of the car. Subaru certainly made it clear to me that they do not care.