[xpragmaticx]

So finished my timing belt job, engine runs great. I also rebuilt PS pump and replaced PCV valve. Everything is smooth, but after I kill the engine, there is a 'puff' of sound like a vacuum is being released. It sounds like it is coming from right at the intake manifold. I didn't mess with any intake parts. When I remove the PCV and start the car, and kill the engine, the noise does not happen? Faulty PCV valve? Only thing that I can think of. And I threw out the old one a few days ago to check with that one.

 

[MrRangerZr1]

My van does that, the noise comes from the throttle body area. When I had my stock OEM intake installed, I did notice the noise but you really have to pay attention. Now I have a short ram intake and the puff of air noise is more audible even if you're standing behind the van.

Was the noise there before? Perhaps you noticed it now but it was there before? I believe the noise is from the throttle body plate closing (when you shut off the van) and blocking the excess air.

 

[conozo]

Does the PVC valve rattle when you shake it. Have to take it off to do this test.

To really find out where it is, you need someone else turing the car off and you listening and feeling in the engine when it happens to narrow it down.

 

[MrRangerZr1]

Also, if the PCV valve is from factory (never been changed) you should change it out. I am assuming you have 100k+ miles on your van so its a good idea to swap it out.

 

[xpragmaticx]

I have determined that it is not the pcv valve. I think the sound may have always been there and I just didn't notice. I was hyper aware listening to Everything after the timing job. When I out the hood down and listen for it, I can still hear it, but deaden ed with sound absorber/heat shield attached to the o the underside of the hood.

 

[AutoJon]

Just a thought. I was replacing spark plugs on my 2014 Odyssey and noticed the belt connected to the power steering was very loose. Was able to pull on it pretty good. After pulling pretty hard on it I did notice the air puff sound. So either the belt is skipping or the power steering pump bearings are locking up. Have someone cut the engine off while you listen

 

[saneeshd]

My bmw does it all the time and i saw other bmw's also does the same. I think the intake vacuum is being released. My Odyssey never does it or the other cars i had.

Please update once you fixed it.

 

[MrRangerZr1]

Just a thought. I was replacing spark plugs on my 2014 Odyssey and noticed the belt connected to the power steering was very loose. Was able to pull on it pretty good. After pulling pretty hard on it I did notice the air puff sound. So either the belt is skipping or the power steering pump bearings are locking up. Have someone cut the engine off while you listen

Wait, why were you pulling on the belt like that?