Hey everyone so my alternator went bad and I replaced it with an Ultima remanufactured one. Little did I know that these are notorious for mot fitting exactly the same as an OEM one. so in order to make it fit, we had to remove the bolt out of the alternator bracket that goes into the water pump. After driving it for a while I hear this whistling, somewhat high pitched sound. I was told it could be a boost leak from the intake manifold gasket due because I guess the alternator bracket bolt not being in the water pump could could cause it to leak? I don't really see how it could its just what I heard. Anyways, I ended up doing a pipe to ear test to see where the sound was coming from and when I put the pipe right on top of the alternator I heard the sound the most. Then I look up these alternators on the internet and I see other cases of people hearing a whistling sound from them too. So im thinking it is the alternator but without the pipe it sounds like it could possibly be from the intake manifold as well. The car runs completely fine and AFR's aren't way off or anything. If I were to test for a boost leak, would a boost leak tester be able to detect a leak in the intake manifold? Thanks for all the help

 

yes, doing a boost leak, you will be able to catch a leak on anything that sees boost from the turbo, including the manifold. i dont see how there is any way at all that the bolt missing from the water pump causes an air leak from the intake manifold, i would be more worried about that bolt not sealing the water pump right and you leaking coolant. but i mean, everything that you are saying is pointing towards the alternator-

- its the only thing that has changed from before and after, you hear it better from the alternator using a tube, a bunch of people say that same alternator whistles, its the alternator in my opinion. no doubt.

and if you had a vacuum leak big enough to where you can hear it (insane) then you would be running so rich, but you stated your afrs are not off......... alternator

 

Thanks for the help man.

 

no problem, thats what were here for