A couple minor problems

[timconsubi07]

I have an 07 subaru impreza 2.5i. I've been driving the car for about 1000 miles now and I have a couple issues but no check engine light. The car is bucking/idling rough but when I am driving it's smooth sailing. Also whenever I get over 3k rpm there is a loud continuous screeching noise coming from (what my mechanic thought) was the alternator and the belts. Just installed a new alternator and the noise is still there whenever I go over 3k. The weird part about it all is that there is no check engine light. I had brought it in a while back when I first bought the car to get the check engine light that came on diagnosed, and it was a cylinder misfire. I was teaching myself how to drive the car and was pretty rough on it so ever since the code was cleared it never came back. Any suggestions as to what I might be looking at here?

Thanks!

[Piggysniffer]

If the car is making boost when screeching it could be an exhaust leak, most likely from the uppipe, or the turbo is doing something nasty or it could have a boost leak from a hose or gasket, the bucking and idling rough is making me think you have a leak somewhere in the intake tract

THAT IS ASSUMING YOUR CAR HAS A turbo ??????

forget all that, just googled your car.... No tu-rd blower lol

[Sandals]

Have you tried revving the engine with your head in the engine bay to see if you can hear where the noise is coming from?