Subaru Repair: subaru engine noise, drain hole, squeel

Question
my wife has a 2004 outback 74000 miles the engine has a shrill squeel around 3-4000 rpms the dealer said it may be the exhaust but that is all good it sounds like it may be a bearing is it possible that it is cam bearing

Answer
Jeffrey, its not a cam bearing as you don't have any,

Subaru is known for a high pitched whistle form the exhaust as you accelerate hard.  Typically happens after about 60k or so, the reason why is complicated, but in a summary the muffler has a drain hole to let water that is collected in the exhaust a place to drain out, as the exhaust system degrades a bit over time the baffling allows air to be pushed out of this drain hole causing a whistle.

I have tried changing the size of the hole to change the pitch it works on some and not on others.  Even if you replace the muffler the noise may still be there as the rest of the exhaust has been degraded a bit

Justin