2011 evo x GSR. This sound does not stop. Its a whine. While in gear or at idle. sometimes it stops. It sounds most the time. 98% of the time. I put a new engine into the car. But this sound started happening after i changed the Alternator. If anyone has encountered this problem please help. Its driving me crazy.

Heres a link.

 

If it started after you changed the alternator, I'm going to go with bad bearing in the alternator or possibly one of the two idler pulleys or the tensioner pulley....

 

checked my pulleys and changed my tensioner. Still nothing

 

Well, try running the car with the serp belt off for a few seconds. It'll be fine without the alternator and waterpump (and PS & A/C) for just a few seconds. If it's quiet, I'd say you got a bad replacement alternator. It happens, even with brand new parts.

 

That sounds like an alternator issue. Like splattj mentioned, run the car with the belt off and see if the sound persists. Or if you pick up a cheapo mechanics stethoscope you can test the different areas.

 

An even cheaper alternative is to use a piece of rubber hose. Before you laugh, it works... lol

 

Thats actually a genius idea lol I'll have to compare the two and see if I wasted $5.88

 

Yeah! I learned that trick from Marco @ Magnus when I was there a few years ago and he had my old red DSM on the dyno to tune it. He used a rubber hose to pin down a vacuum leak which was caused by a torn lower injector seal. I've used that method since, works well