There'* an annoying whistling sound coming from the passenger side when I accelerate softly, moderately, or hard. It'* definitley in the engine compartment. It almost sounds like a supercharger, but obviously isn't.

It'* driving me nuts.

I assume my PCV is OK because I can remove the oil fill cap effortlessly when the engine is running.

It'* most likely the PCV, way it'* sitting there, o ring or cap.

I'd attribute it to the PCV first.. Mine didn't vacuum when it wasn't seated 100%

So, what do you suggest? A new one with the o-rings?

I'm puzzled how it could be bad or not seated if I can remove the oil fill cap without a struggle (same as if the engine was not running).

All I know is my experience.

I swapped mine out. And had a whistle, but only at the high rpm'* right at the shift point. Removed..reinstalled.. identically as far as I could tell and no more whistle.

At this point..I'd suggest you inspect for any oddities.

Another thought..

Vacuum line... but what vacuum is over there on your motor???????

The main one I know of is the one going to the break booster from the back of the UIM. I'll check that one too.

Also the o ring on the cap itself.

What cap?

Mark, your car is just happy. Why can't you just let it have it'* fun?...life is hard enough... Maybe you should join in and just whistle a happy tune.... :P










edit; The oil fill cap.

Just to chime in, my wife'* 2001 GP GT with the L36 does this too, and it turned out to be the alternator. Since fixing it means replacing the alternator, and the alternator is otherwise just fine, and the whistling isn't too bad, we just left it. It'* been about a year now, no other problems, just a light whistling from the alternator. So you might have the same thing. It'* the right location, -passenger side.