4agze intake manifold making a strange noise..

[matt_spitfire]

4agze gurus: Anyone have any idea what may be causing this sound? It’s coming from the intake manifold on a ae101 4agze map model engine. Sounds like a pipe trying to suck up fluid.. 

 

please note engine always has an air filter on it just removed to record the video. 

 

Only makes the noise on idle after cold start knocks off. Seems to disappear when’s revs are on an comes back when revs drop.

video: https://youtu.be/_u0iICeAu_c

[matt_spitfire]

Problem solved, excess vacuum inside the intake manifold.

[Seedy Al]

How do you get excess vacuum? 

[bigfoot]

1 hour ago, Seedy Al said:

How do you get excess vacuum? 

Not enough boost?