strange vac. in crankcase 98 Buick 3800

[chevynut]

after warm ups you began to hear noise in engine sounding like a bad belt or water pump noise by accident we removedthe oil fill cap and the noise stopped,replace the oil fill cap.engine generates suction and noise returns.intake cracked???

[mbaskett]

I wouldn't peg it ona cracked intake right away... You're more likely to have a vacuum leak, usually caused by the degradation of rubber in any vacuum hoses over time.. That's the first place I'd look.

Try the old carb cleaner trick... spray it on places you think the leak is coming from... when you hit the spot, you'll hear the engine rev a bit (from burning the carb cleaner)...

[chevynut]

still have not found problem,removed intake,no sign of cracks replaced gaskets,as soon as I started the engine,it built up vac. in the crankcase

[drive-ability]

If vacuum seems to be the cause,

The PCV is hidden in the intake. You can get to it and its been a while but I think its on the passenger side under a plastic cap which you turn to gain access. It just may be flowing a lot or just vibrating.

[chevynut]

checked that first,even replaced pcv valve nothing changed

[chevynut]

found the problem,thanks

[drive-ability]

What resolved your problem???

[chevynut]

no o'ring under pcv valve

[drive-ability]

My first reply was to check the PCV. This happens at least once a year where I work. The line techs are great at heavy engine repair but not so good at the details. I have seen one guy do it 3 times and not notice it until it comes back. A PCV used to be a valve, now its hidden, has an o-ring and a spring???? Go figure

[TrickyTransAm]

Hi - Newbie here. Reviving an old thread.

I've got the same problem with a 98 Bonnie with the POS Series II in it.

Does anyone else have a solution for this problem?

Ive put in a new Reman 3800 into my moms car, with an aftermarket upper intake, and its got that strange PCV Valve Buzz.

Worse, its developed a Ton of Crankcase vacuum.
The Dealership's 1 week fix was the O-ring - and then it returned.

Now, my late fathers 99 Tahoe developed the same PCV valve buzz.

Im almost thinking Delco is putting a weak spring, or a bad design to where the valve goes into resonance. But upon replacement...it exibits the same thing.

Any other thoughts?

Thanks!
Corey