Originally Posted by venom

If it started doing it after intake install then it may be the intake pipe banging against something in the engine bay. Remember when you rev the engine it moves but with it in gear it will move even more. You might think intake has enough clearance but it may be banging against something.

One more thing how many miles on the belts? Almost forgot I once had a noise like that and it turned out to be idler pulley, bearing was going out. To test spray some wd40 in the bearing and see if stops temporary as it will not stop squeak for long but should be enough to see it thats the problem.