97 Lesabre whistle /squeal driving me crazy

[motocip]

I have a 97 Lesabre with a Series II 3.8 motor. 209,000 miles and running good, (not original motor or trans).

The problem I have is sometimes the motor makes this sound I will call a whistle or a squeal that is quite noticable. This occurs when the car is warm. I have noticed the following:

When in gear and idling, applying a load or accelerating makes it go away.
When in neutral nothing makes it go away.

The sound is the loudest if you stand under the car while on a lift. The noise seems to be coming from the bellhousing area and is loud enough that it starts to hurts my ears. I have noticed when I remove the pcv valve it goes away. The pcv valve is new and there are no missing o-rings as I have read in other posts.

Also, when the motor is running and you remove the oil fill cap there is ALOT of suction, is this normal? Need help.

[C.Money]

possible vacuum leak, or trans is whining....does ur trans slip at all? that could be the reason it whines, chipped gear, my regal 3.8 did that

[motocip]

I don't think my trans is bad because it operates smoothly. I could be wrong about the sounds location, it seems to be the loudest from underneath. A good way to describe it is if you've ever been out in the country and heard frogs at night, it sounds just like that.

[rustbucket]

The air conditioner clutch can cause a squeal (when not running AC). But I think mine was higher pitched than frogs, more like crickets. If your AC still works, try turning it on and see if squeal changes.

[-dark_knight-]

A simular problem happend with my wifes car. Her 97 Lesaber was making a high pitched noise we were able to find a dry rotted vacum hose. I replaced the hose and the noise went away.

[motocip]

I looked further into the archives and took a chance on a pcv valve kit from the dealer. The GM part number is 89017274 and cost just under $23.00 including tax. The kit comes with two new o-rings, pcv valve, spring, and new housing. I installed it and the whistle is gone! I can remove the oil fill cap and there is no more suction either. I think the o-ring I was using on the pcv valve too thin. The o-ring that comes in the kit is thicker and seals better. Thanks for the help.

PS; I am hopeful that it may clear my check engine light for code 401 which is insufficient flow EGR. I will keep you posted. I read that the pcv valve can sometimes cause this code.

[motocip]

Code 401 went away after a few warm up cycles. No more check engine light.