Whistle/Whirr/Suction sound coming from engine 1990 Olds Cut

1990 Olds Cutlass Ciera, v6

I was a bad boy and didn't check my oil until it was too late. The engine started making this whistle/whirr/suction sound. The pitch of the sound is a direct relation to the RPM - faster RPM, higher pitch. Exactly related.

I added oil. It needed about 1.25 quarts. The sound is still there, but it seems like it might be a little more quiet since I added the errrl.
What could the problem be? 1.25 quarts low? That didn't cause any problems I can almost guarentee.


This engine (if it's the 3.1) is known for intake leaks and head gasket problems.

The whistle increases with engine speed, or the whir? Generally a vacuum leak will decrease with engine speed. Does the whistle stop even for a split second if you goose the throttle all the way down for a moment? If I hit it hard, the engine noise is louder than the whistle. Actually it seems to have decreased more...


It does sound almost like the air intake did on my cousin's Mustang GT. Whistle/whirr was the same noise... I don't know exactly how to describe it, but it's one sound.

It sounds like it could be an intake leak.