Noise from oil filler while running with cap removed

[x75thxmiltown]

I don't know if I'm being too anal about this but I have some noise coming from my oil fill tube while the engines running and with the oil cap removed. There seems to be a slight vacuum when I put my hand over the port and the sound ceases to exist. The noise is kind of high pitched and pulses with the engine. I have a video of it that I will upload when I figure out how to do it. Any advice or opinions would be much appreciated. Thanks

[Techno Duck]

This is normal, just a function of the pistons moving up and down.

[nize]

+1 normal.

[x75thxmiltown]

Ok I figured as much I just thought I would ask since last fall I had a so called "944 restorer" look at it to buy and he said it wasn't normal. Of course this is my first car from the 80's so expected some noise but not a high pitch pulsating whine like this... Thanks for the piece of mind but I will upload the video anyways just as a precaution!

[x75thxmiltown]

https://www.youtube.com/watch?v=-qPKBCHy3Cc&feature=youtu.be

The above link is a video of the noise i get, also is the ticking that loud normal? I assume it is due to the injectors and being a 26 year old car.
Let me know what you guys think.

[kdjones2000]

That is a bit unusual.

Almost sounds like an air leak / vacuum leak coming from somewhere.

Look for some threads on the forum about how to check for leaks.

[x75thxmiltown]

That's what I thought. Like I said before it's not a steady sound, it pulses/whooshes which you can't hear in the video. I will check into the vacuum leak theory when I get some time