02 OUTBACK engine hollow knocking sound when warm. replaced pistons+tensioner already

[rjp98outlook]

Hi.

I have read a few discussions on Subaru engine noise in this forum and I am hoping someone can help. I also have a noise problem in my 02 outback that I can't live with. I have only 26K miles on it and have been to the dealer 3 times already. The noise is a hollow knocking sound that is quite subtle (but is slowly turning my brain into jelly) and only occurs when the car is ***fully warmed up*** and under light load (like around 2500 to 3000 rpm with foot just barely on accelerator -- almost coasting) Sounds like something is loose and floating/knocking. Subaru already replace the timing belt tensioner and bracket, and just last week they replace two of the pistons (#2 and #4) with special pistons designed to not slap. This had no effect at all on the noise. As I suspected, it was not piston slap in the first place. What a waste of Subaru's money to replace these unnecessarily under warranty. What can I do now? Is this just how these engines are supposed to sound? Also, I have a manual trans which may exagerate the problem according to the dealer.

 

Thanks

Rich